[clang] [Clang][Sema] Handle invalid variable template specialization whose type depends on itself (PR #134522)

[Shafik Yaghmour via cfe-commits]

shafik wrote:

This was flagged in the following issue: https://github.com/llvm/llvm-project/issues/139067#issuecomment-2865530760

https://github.com/llvm/llvm-project/pull/134522