fix: remove the job network even when container removal overruns (#1318)

Job teardown ran every step on one shared minute. When removing the job container took longer, the network removal ran on an expired context and the network stayed behind until the orphan reclaim, which only takes networks older than `workdir_cleanup_age`, 24h by default. All that time it held a subnet of the daemon's address pool.

The job and service containers are now removed in parallel, and the docker proxy sweep, the network and the volumes get a fresh budget after them. The idle reclaim takes unused networks and volumes once they are 10 minutes old, and network removal treats a network that is already gone as removed.

Reviewed-on: https://gitea.com/gitea/runner/pulls/1318
Reviewed-by: bircni <[email protected]>
Co-authored-by: silverwind <[email protected]>

README.md

@@ -368,7 +368,7 @@ While the runner is idle it cleans up after earlier jobs:
 - when `container.bind_workdir` is enabled, stale task workspace directories older than `runner.workdir_cleanup_age` are removed (default: `24h`; set `0` to disable)
 - only purely numeric subdirectories under `container.workdir_parent` are treated as task workspaces and may be removed
 - cleanup assumes `container.workdir_parent` is not shared across multiple runners
-- on runners that use docker, per-job networks left behind by jobs the runner did not live to tear down are removed, identified by the `com.gitea.runner.uuid` label carrying this runner's uuid
+- on runners that use docker, per-job networks and volumes left behind by jobs the runner did not live to tear down are removed once unused and 10 minutes old, identified by the `com.gitea.runner.uuid` label carrying this runner's uuid
 - on runners with `kubernetes` labels, job pods with that label older than `runner.workdir_cleanup_age` are removed the same way, together with their Secrets
 - cleanup runs every `runner.idle_cleanup_interval` (default: `10m`; set `0` to disable), and setting either knob to `0` disables all of the above