With cache_delete set, DELETE /api/git/{upstream}/{repo} removes one
repository from the git cache and /ui/git gets a Delete button per
repository. The repository is moved aside under the cache's lock, as
eviction does, so the next clone fetches it again. One that a clone, a
fetch or a client is using answers 409. The response names the
repository and the bytes freed.
A view ran four git processes for each repository whose state wasn't
cached, with no limit, and each concurrent view did the same.
RepositoryState now runs one read at a time and gives up with its
context. The page reads for at most two seconds, lists the rest without
branches and commits, and says how many are left; the cache keeps what
was read, so each reload reads more.
Also test that an upstream, a repos pattern and a repository with
uppercase letters are listed as spelled, and correct two comments.
The summary said "1 repositories" and counted the size of repositories it
didn't list. A repository whose state can't be read is no longer read on
every page view, only after its next upstream check.
/ui/git lists the git cache's repositories with their upstream, clone URL,
size, last check and use, requests served and the last refresh error. The
per-ecosystem cache size and artifact gauges report the git cache as
ecosystem="git".
