[clang] [Clang][Sema] Diagnose variable template explicit specializations with storage-class-specifiers (PR #93873)

[Krystian Stasiowski via cfe-commits]

sdkrystian wrote:

> non-static class member

@alexfh Missed this one :) Opened a PR to fix this [here](https://github.com/llvm/llvm-project/pull/97425).

https://github.com/llvm/llvm-project/pull/93873