Bump tools/OpenROAD from 0064f2d to 21008b8

Bumps [tools/OpenROAD](https://github.com/The-OpenROAD-Project/OpenROAD) from `0064f2d` to `21008b8`.
- [Release notes](https://github.com/The-OpenROAD-Project/OpenROAD/releases)
- [Commits](The-OpenROAD-Project/OpenROAD@0064f2d...21008b8)

---
updated-dependencies:
- dependency-name: tools/OpenROAD
  dependency-version: 21008b83979ace48ae803bc386235f56219fd1a9
  dependency-type: direct:production
...

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

Author: dependabot[bot]