Bump third_party/prjxray from `78565b6` to `6bc8d8a`
Bump third_party/prjxray from `78565b6` to `6bc8d8a`

Bumps [third_party/prjxray](https://github.com/SymbiFlow/prjxray) from `78565b6` to `6bc8d8a`.
- [Release notes](https://github.com/SymbiFlow/prjxray/releases)
- [Commits](https://github.com/SymbiFlow/prjxray/compare/78565b6d23bd89cbaf362ea550622b56ba738290...6bc8d8ad0284bb22d579e0524ff8e96266f1d60a)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
SymbiFlow/symbiflow-xc-fasm2bels