Bump externals/llvm-project from 612aed5 to ecad3c5

Bumps [externals/llvm-project](https://github.com/Xilinx/llvm-project) from `612aed5` to `ecad3c5`.
- [Commits](Xilinx/llvm-project@612aed5...ecad3c5)

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

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