The repo's .gitattributes (inherited from upstream) routes certain paths
through git-lfs. Gitea's LFS store doesn't hold those blobs, so on
checkout the smudge filter tries to download them, 404s, and leaves git
in a state where subsequent 'git fetch' calls appear to succeed but
don't actually populate refs.
Run 89 was bitten by this: checkout 'succeeded' with an LFS smudge
fatal, then 'git fetch upstream develop' ran silently, 'git merge
--ff-only upstream/develop' failed because upstream/develop ref
didn't exist locally, and the workflow logged a misleading warning
blaming a divergence that wasn't there.
Setting GIT_LFS_SKIP_SMUDGE=1 keeps LFS pointers as-is. We don't need
image bytes to ff-merge and diff refs.
Cobb
e710e7d669