[llvm] [VPlan] Remove unused inferScalarTypeForRecipe declaration (NFC). (PR #194450)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `flang-aarch64-sharedlibs` running on `linaro-flang-aarch64-sharedlibs` while building `llvm` at step 7 "test-build-unified-tree-check-flang-rt".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/80/builds/22209

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

```
Step 7 (test-build-unified-tree-check-flang-rt) failure: test (failure)
******************** TEST 'flang-rt-Unit :: Runtime/./RuntimeTests/151/304' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/home/tcwg-buildbot/worker/flang-aarch64-sharedlibs/build/runtimes/runtimes-bins/flang-rt/unittests/Runtime/./RuntimeTests-flang-rt-Unit-2284305-151-304.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=304 GTEST_SHARD_INDEX=151 /home/tcwg-buildbot/worker/flang-aarch64-sharedlibs/build/runtimes/runtimes-bins/flang-rt/unittests/Runtime/./RuntimeTests
--

Running main() from /home/tcwg-buildbot/worker/flang-aarch64-sharedlibs/llvm-project/third-party/unittest/googletest/src/gtest_main.cc
Note: This is test shard 152 of 304.
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from ExternalIOTests
[ RUN      ] ExternalIOTests.TestUCS

fatal Fortran runtime error(/home/tcwg-buildbot/worker/flang-aarch64-sharedlibs/llvm-project/flang-rt/unittests/Runtime/ExternalIOTest.cpp:857): I/O error (errno=28): No space left on device

--
exit: -6
--
shard JSON output does not exist: /home/tcwg-buildbot/worker/flang-aarch64-sharedlibs/build/runtimes/runtimes-bins/flang-rt/unittests/Runtime/./RuntimeTests-flang-rt-Unit-2284305-151-304.json
********************


```

</details>

https://github.com/llvm/llvm-project/pull/194450