Merge branch 'doc-troubleshoot-git-curl-http-2' into 'master'

Docs: Troubleshoot HTTP/2 problems in get_sources CI job step

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/130408



Merged-by: Marcel Amirault <mamirault@gitlab.com>
Approved-by: Marcel Amirault <mamirault@gitlab.com>
Reviewed-by: Marcel Amirault <mamirault@gitlab.com>
Co-authored-by: Katrin Leinweber <kleinweber@gitlab.com>