fix(ci): use code.forgejo.org instead of the docker hub (#762)

- use https://code.forgejo.org/forgejo/hello-world-docker-action/ that is a copy of https://github.com/actions/hello-world-docker-action/ with a patch to not use the docker hub
- node:16-buster-slim replaced with code.forgejo.org/oci/node:22 and checked that whatever is tested with it is not likely to be disturbed by the change in version
- change base images of Dockerfile to be from code.forgejo.org/oci/ equivalents
- use code.forgejo.org/forgejo/runner:8 instead of catthehacker/ubuntu:runner-latest

To test services:

- use code.forgejo.org/oci/bitnami/postgresql:16 instead of postgres:12
- use code.forgejo.org/oci/apache-git:1 instead of nginx:latest

Skip flaky test and [open an issue for it](https://code.forgejo.org/forgejo/runner/issues/763).

---

<!--start release-notes-assistant-->
<!--URL:https://code.forgejo.org/forgejo/runner-->
- bug fixes
  - [PR](https://code.forgejo.org/forgejo/runner/pulls/762): <!--number 762 --><!--line 0 --><!--description Zml4KGNpKTogdXNlIGNvZGUuZm9yZ2Vqby5vcmcgaW5zdGVhZCBvZiB0aGUgZG9ja2VyIGh1Yg==-->fix(ci): use code.forgejo.org instead of the docker hub<!--description-->
<!--end release-notes-assistant-->

Reviewed-on: https://code.forgejo.org/forgejo/runner/pulls/762
Reviewed-by: Michael Kriese <michael.kriese@gmx.de>
Co-authored-by: Earl Warren <contact@earl-warren.org>
Co-committed-by: Earl Warren <contact@earl-warren.org>

act/runner/runner_test.go

@@ -407,6 +407,7 @@ func TestRunner_DockerActionForcePullForceRebuild(t *testing.T) {
 }
 
 func TestRunner_RunDifferentArchitecture(t *testing.T) {
+	t.Skip("Flaky see https://code.forgejo.org/forgejo/runner/issues/763")
 	if testing.Short() {
 		t.Skip("skipping integration test")
 	}