Merge branch '270770-fix-feature-flag-error' into 'master'

Remove invite_email_experiment feature flag

See merge request gitlab-org/gitlab!45706

config/feature_flags/development/invite_email_experiment.yml

----
-name: invite_email_experiment
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/39628
-rollout_issue_url:
-group: group::acquisition
-type: development
-default_enabled: false