[clang] [C++20] [Modules] [Driver] Don't enable -fdelayed-template-parsing by default on windows with C++20 modules (PR #69431)

[Petr Hosek via cfe-commits]

petrhosek wrote:

This broke the following tests on Windows:
```
llvm-libc++-static-clangcl.cfg.in :: libcxx/atomics/diagnose_invalid_memory_order.verify.cpp
llvm-libc++-static-clangcl.cfg.in :: libcxx/fuzzing/random.pass.cpp
llvm-libc++-static-clangcl.cfg.in :: std/depr/depr.c.headers/math_h.pass.cpp
llvm-libc++-static-clangcl.cfg.in :: std/numerics/c.math/cmath.pass.cpp
```

https://github.com/llvm/llvm-project/pull/69431