[clang-tools-extra] [clangd] [C++20] [Modules] Don't reuse prebuilt module files on windows (PR #193426)

[kadir çetinkaya via cfe-commits]

kadircet wrote:

FWIW, this is also triggering breakages in build bots, https://lab.llvm.org/buildbot/#/builders/134/builds/48761. @ingomueller-net can you check if your PR is meant to fix that failure too ?

https://github.com/llvm/llvm-project/pull/193426