Ref T13448. When "Fetch Refs" is configured:
- We switch to a narrow mode when running "ls-remote" against the local working copy. This excludes surplus refs, so we'll incorrectly detect that the local and remote working copies are identical in cases where the local working copy really has surplus refs.
- We rely on "--prune" to remove surplus local refs, but it only prunes refs matching the refspecs we pass "git fetch". Since these refspecs are very narrow under "Fetch Only", the pruning behavior is also very narrow.
- When listing local refs, always list everything. If we have too much stuff locally, we want to get rid of it.
- When we identify surplus local refs, explicitly delete them instead of relying on "--prune". We can just do this in all cases so we don't have separate "--prune" and "manual" cases.