[clang] [Clang][Sema] Fix crash when 'this' is used in a dependent class scope function template specialization that instantiates to a static member function (PR #87541)

[Krystian Stasiowski via cfe-commits]

sdkrystian wrote:

@rupprecht That's unintended, will revert and address it.

https://github.com/llvm/llvm-project/pull/87541