Bump llvm-project from 7326995 to 20a6720

Bumps [llvm-project](https://github.com/Xilinx/llvm-project) from `7326995` to `20a6720`.
- [Commits](Xilinx/llvm-project@7326995...20a6720)

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

Signed-off-by: dependabot[bot] <[email protected]>