- checkbranch: fetch master from the base repo clone_url instead of the
PR head remote (origin), which on GitHub is the fork for fork PRs
- replace the curl comment snippets with sticky_comment.py: stdlib-only,
works with the REST API on both platforms, and keeps the
skip_unchanged/ignore_empty behavior of the old action
Two bugs prevented the 'Core Library Line Count' bot from working:
1. checkbranch fetched master from github.com/tinygrad/tinygrad instead of
the local Gitea instance. Since the Gitea mirror lags behind GitHub,
every PR appeared 'behind' and the szdiff job was always skipped.
2. marocchino/sticky-pull-request-comment@v3 uses GraphQL to find existing
comments, but Gitea has no GraphQL API (returns 404). Both the szdiff
and rebase comment steps failed with '404 page not found'.
Fix 1: fetch origin/master (the local Gitea repo) instead of adding a
remote to github.com.
Fix 2: replace the third-party action with curl calls to the Gitea REST
API (GET/POST/PATCH /repos/.../issues/.../comments), which fully supports
the sticky-comment pattern (find existing, update or create).