cmd/go/internal/modfetch/codehost: test fails with git 2.47.1 [1.22 backport]

[gopherbot]

@ianlancetaylor requested issue #71261 to be considered for backport to the next 1.22 minor release.

@gopherbot Please open backport issues

This test is failing with older versions of Go, presumably because of a newer versions of git. We should backport the fix to supported versions, so that people using older Go versions don't complain when the update to a newer version of git.

[gopherbot]

Change https://go.dev/cl/642695 mentions this issue: [release-branch.go1.22] cmd/go/internal/modfetch: do not trust server to send all tags in shallow fetch