actions: verify runner config options for the container

- is not restricted to --volume (can use --env, etc.)
- --volume is sanitized with valid_volumes

actions/example-config-options/runner-config.yaml

@@ -0,0 +1,30 @@
+
+log:
+  level: debug
+
+runner:
+  file: .runner
+  capacity: 1
+  env_file: .env
+  timeout: 3h
+  insecure: false
+  fetch_timeout: 5s
+  fetch_interval: 2s
+  labels: ["docker:docker://code.forgejo.org/oci/node:20-bookworm"]
+
+cache:
+  enabled: false
+  dir: ""
+  host: ""
+  port: 0
+
+container:
+  network: ""
+  privileged: false
+  options: "--volume /srv/example-config-options-volume-valid:/srv/example-config-options-volume-valid --volume /srv/example-config-options-volume-invalid:/srv/example-config-options-volume-invalid --env FROB=NITZ"
+  workdir_parent:
+  valid_volumes: ["/srv/example-config-options-volume-valid"]
+  docker_host: ""
+
+host:
+  workdir_parent: