[clang] Revert "[clang] Reland: Instantiate concepts with sugared template arguments (#101782)" (PR #102551)

[Fangrui Song via cfe-commits]

MaskRay wrote:

The description specifies "Reverted due to both regression reported on PR and https://github.com/llvm/llvm-project/issues/102353" but somehow the commit message does not include the reason.
(I just tried to look at reverts without reasons and remind the authors.)

https://github.com/llvm/llvm-project/pull/102551