Bump tools/OpenROAD from 74dbef2 to b6c92cb

Bumps [tools/OpenROAD](https://github.com/The-OpenROAD-Project/OpenROAD) from `74dbef2` to `b6c92cb`.
- [Release notes](https://github.com/The-OpenROAD-Project/OpenROAD/releases)
- [Commits](The-OpenROAD-Project/OpenROAD@74dbef2...b6c92cb)

---
updated-dependencies:
- dependency-name: tools/OpenROAD
  dependency-version: b6c92cb46620e3918832b3b6bb6d7807c1e4afe3
  dependency-type: direct:production
...

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

Author: dependabot[bot]