New features

• Add --runs-on for executing remote commands using SSH.
• Maintain runs-on context for all commands in the run.
• Update runs-on to support Docker Desktop and Fedora/RHEL.
• Add avocado prune command to clean up abandoned state.
• Add clean --force option.
• Update provision to support remote signing.

Improvements

• Use bindfs for the source directory for permission handling.
• Install target-sysroot for any sdk.compile.
• Tune NFS server settings.
• Cross SDK arch runs-on checking.
• Update SDK install stamp to track architecture.
• Update remote to support /bin/sh.
• Improve bindfs error messages.