Merge branch 'doc-ghcr-TOOMANYREQUESTS-in-CS-container-scanning' into 'master'

Docs: Improve "Java database mirror" section

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/168367



Merged-by: Phillip Wells <pwells@gitlab.com>
Approved-by: Igor Frenkel <ifrenkel@gitlab.com>
Approved-by: Phillip Wells <pwells@gitlab.com>
Co-authored-by: Katrin Leinweber <kleinweber@gitlab.com>