Merge branch '402242-use-glavatar-fallback-for-sso-projects' into 'master'

Use fallback when project/group avatar fails to load

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/119285



Merged-by: Ezekiel Kigbo <3397881-ekigbo@users.noreply.gitlab.com>
Approved-by: Matthew Nearents <mnearents@gitlab.com>
Approved-by: Ezekiel Kigbo <3397881-ekigbo@users.noreply.gitlab.com>
Co-authored-by: Kushal Pandya <kushal@gitlab.com>