* replace workflow action from ytdl-patched with local workflows/rebaser.yml
* rebase upstream onto nightly, so appending new upstream commits
* local workflow also avoids deprecated 3rd-party actions.
* make Build callable but not scheduled
* make Build receive commit SHA from caller
* make Rebase pass commit SHA to Build
* Don't set GH output from update-version.py
* No rebase is still success
* Allow scheduled Rebase to invoke Build