Latest Glamour has slightly changed logic in line length / wrapping,
resulting test failures due to string mismatch. Update tests and bump
dependency to v0.8.0, and others to the bare minimal level as generated
by `go mod tidy`.
This was detected then building the GitHub cli package `gh` in Debian
started to fail with src:golang-github-charmbracelet-glamour 0.8.0-1.
Closes: #10179
This commit expands on @nobe4 initial work by bringing the owner and repository name to the most obvious issue and PR number output use cases before making a second pass for any edge cases.
For asserting command output, exact string matches are preferred in most cases. In cases when a pattern match is needed, the test can use regexp ad hoc.
If the `--repo` flag is specified, then the user intends to select a
repository other than the current one. In that case, it doesn't make
sense to fall back to detecting the PR belonging to the current branch,
so throw a descriptive error instead.
