refactor(github): group the variant modules and drop the blind-except

variant_bundle_limits.py next to variant_bundles.py formed the prefix group
'variant', which the structure lint reads as a folder in disguise. It stayed
green locally because that lint asks git ls-files: the new file was untracked
through every quality run and only became visible once committed. CI saw it
immediately - the sole failure of run 30675284663.

Both move to utils/github/variant/ as bundles.py and limits.py, and the test
mirrors along.

The BLE001 per-file ignore is removed rather than repointed. parse_size raises
humanfriendly.InvalidSize for a malformed string and TypeError only for a
non-string, and the value reaching it is always str - so the catch-all was
never needed. Measured, not assumed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/github/resolve/output_apps.sh

@@ -15,7 +15,7 @@ source "${REPO_ROOT}/scripts/meta/env/python.sh"
 apps="$(./scripts/meta/resolve/apps.sh)"
 [[ -n "$apps" ]] || apps='[]'
 
-matrix="$(printf '%s' "$apps" | "${PYTHON}" -m utils.github.variant_bundles)"
+matrix="$(printf '%s' "$apps" | "${PYTHON}" -m utils.github.variant.bundles)"
 [[ -n "$matrix" ]] || matrix='[]'
 
 echo "apps=$matrix" >>"$GITHUB_OUTPUT"