Bump llvm-project from 4b36487 to ad4697c

Bumps [llvm-project](https://github.com/Xilinx/llvm-project) from `4b36487` to `ad4697c`.
- [Commits](Xilinx/llvm-project@4b36487...ad4697c)

---
updated-dependencies:
- dependency-name: llvm-project
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>