Enable Forgejo Actions support

Add FORGEJO__actions__ENABLED and DEFAULT_ACTIONS_URL environment
variables to enable Actions/CI workflows in Forgejo.

This is required for DEV-334 CI/CD workflow implementation.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/forgejo/forgejo-deployment.yaml

@@ -66,6 +66,10 @@ spec:
           value: forgejo.basicstack.de
         - name: FORGEJO__service__DISABLE_REGISTRATION
           value: "true"
+        - name: FORGEJO__actions__ENABLED
+          value: "true"
+        - name: FORGEJO__actions__DEFAULT_ACTIONS_URL
+          value: "https://code.forgejo.org"
         resources:
           requests:
             cpu: 250m