Snapshotting: Skip .git directories and files

`.git` can be a directory (in the normal case) or a file (if it is in
a git worktree).  We should not include it, because it can become very
large.

PiperOrigin-RevId: 821615296

Author: OSS-Fuzz Team

infra/base-images/base-builder/indexer/manifest_types.py

@@ -432,6 +432,10 @@ def _save_dir(
                 # Don't copy over the seed corpus -- it's not necessary.
                 continue
 
+              if "/.git/" in root or root.endswith("/.git"):
+                # Skip the .git directory -- it can be large.
+                continue
+
               file = pathlib.Path(root, file)
               if exclude_build_artifacts and _is_elf(file):
                 continue