Remove ci_secrets_management as licensed feature flag

Related to https://gitlab.com/gitlab-org/gitlab/-/issues/273362.

config/initializers/0_inject_feature_flags.rb

@@ -14,7 +14,6 @@ if Gitlab.ee? && Gitlab.dev_or_test_env?
   # being unique to licensed names. These feature flags should be reworked to
   # be "development" with explicit check
   IGNORED_FEATURE_FLAGS = %i[
-    ci_secrets_management
     feature_flags_related_issues
     group_coverage_reports
     group_wikis

ee/config/feature_flags/licensed/ci_secrets_management.yml

----
-name: ci_secrets_management
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/42055
-rollout_issue_url:
-group: group::release management
-type: licensed
-default_enabled: true