[clang] [lld] [llvm] [CMake] Remove references to GnuWin32 tools from `LLVM_LIT_TOOLS_DIR` (PR #217657)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-flang-ppc64-aix` running on `aix-ppc64` while building `clang,lld,llvm` at step 7 "test-build-unified-tree-check-clang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/231/builds/936

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 7 (test-build-unified-tree-check-clang) failure: test (failure)
******************** TEST 'Clang :: ClangScanDeps/modules-context-hash-outputs.c' FAILED ********************
Exit Code: 2

Command Output (stdout):
--
# RUN: at line 4
rm -rf /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp
# executed command: rm -rf /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp
# RUN: at line 5
split-file /home/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/modules-context-hash-outputs.c /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp
# executed command: split-file /home/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/modules-context-hash-outputs.c /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp
# RUN: at line 6
sed "s|DIR|/home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp|g" /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp/cdb.json.template > /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp/cdb.json
# executed command: sed 's|DIR|/home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp|g' /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp/cdb.json.template
# RUN: at line 8
/home/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/clang-scan-deps -compilation-database /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp/cdb.json -j 1    -format experimental-full > /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp/deps.json
# executed command: /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/clang-scan-deps -compilation-database /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp/cdb.json -j 1 -format experimental-full
# RUN: at line 10
cat /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp/deps.json | sed 's:\\\\\?:/:g'    | "/home/llvm/llvm-external-buildbots/workers/env/bin/python3.11" /home/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/utils/scan-deps-filter.py --fields=clang-module-deps,command-line,context-hash,input-file,name    | /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/FileCheck -DPREFIX=/home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp /home/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/modules-context-hash-outputs.c
# executed command: cat /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp/deps.json
# executed command: sed 's:\\\\\?:/:g'
# executed command: /home/llvm/llvm-external-buildbots/workers/env/bin/python3.11 /home/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/utils/scan-deps-filter.py --fields=clang-module-deps,command-line,context-hash,input-file,name
# .---command stderr------------
# | Traceback (most recent call last):
# |   File "/home/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/utils/scan-deps-filter.py", line 127, in <module>
# |     main()
# |   File "/home/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/utils/scan-deps-filter.py", line 111, in main
# |     data = json.load(f)
# |            ^^^^^^^^^^^^
# |   File "/opt/freeware/lib64/python3.11/json/__init__.py", line 293, in load
# |     return loads(fp.read(),
# |            ^^^^^^^^^^^^^^^^
# |   File "/opt/freeware/lib64/python3.11/json/__init__.py", line 346, in loads
# |     return _default_decoder.decode(s)
# |            ^^^^^^^^^^^^^^^^^^^^^^^^^^
# |   File "/opt/freeware/lib64/python3.11/json/decoder.py", line 337, in decode
# |     obj, end = self.raw_decode(s, idx=_w(s, 0).end())
# |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
# |   File "/opt/freeware/lib64/python3.11/json/decoder.py", line 353, in raw_decode
# |     obj, end = self.scan_once(s, idx)
# |                ^^^^^^^^^^^^^^^^^^^^^^
# | json.decoder.JSONDecodeError: Expecting ',' delimiter: line 445 column 2 (char 18109)
# `-----------------------------
# error: command failed with exit status: 1
# executed command: /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/FileCheck -DPREFIX=/home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp /home/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/modules-context-hash-outputs.c
# .---command stderr------------
# | FileCheck error: '<stdin>' is empty.
# | FileCheck command line:  /home/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/FileCheck -DPREFIX=/home/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/modules-context-hash-outputs.c.tmp /home/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/modules-context-hash-outputs.c
# `-----------------------------
# error: command failed with exit status: 2
...

```

</details>

https://github.com/llvm/llvm-project/pull/217657