Remove geo_token_user_authentication feature flag

Changelog: other
EE: true

config/feature_flags/development/geo_token_user_authentication.yml

----
-name: geo_token_user_authentication
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/79431
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/351450
-milestone: '14.8'
-type: development
-group: group::geo
-default_enabled: true

ee/lib/ee/gitlab/auth/auth_finders.rb

@@ -8,7 +8,6 @@ module EE
         extend ::Gitlab::Utils::Override
 
         def find_user_from_geo_token
-          return unless ::Feature.enabled?(:geo_token_user_authentication, default_enabled: :yaml)
           return unless geo_api_request?
 
           token = current_request.authorization

ee/spec/lib/ee/gitlab/auth/auth_finders_spec.rb

@@ -105,17 +105,5 @@ RSpec.describe EE::Gitlab::Auth::AuthFinders do
         expect { subject }.to raise_error(::Gitlab::Auth::UnauthorizedError)
       end
     end
-
-    context 'when the geo_token_user_authentication feature flag is disabled' do
-      before do
-        stub_feature_flags(geo_token_user_authentication: false)
-      end
-
-      it 'returns immediately' do
-        expect(::Gitlab::Geo::JwtRequestDecoder).not_to receive(:geo_auth_attempt?)
-        expect(::Gitlab::Geo::JwtRequestDecoder).not_to receive(:new)
-        expect(subject).to be_nil
-      end
-    end
   end
 end