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

[Reid Kleckner via cfe-commits]

rnk wrote:

I still support disabling delayed template parsing by default in all configurations. Ultimately, this feature is a source of bugs, and we should start the clock on its deprecation and removal. This, of course, involves real work, and I haven't allocated any time (mine or others') to it.

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