refactor: remove dead code and consolidate tests (#1335)

Removes dead code and redundant logic and consolidates tests, so there is less to read and maintain. No behavior change.

1. **act/runner**: inline single-use wrappers, compile regexes once instead of per call, embed the trampoline as a string, drop the unused legacy result of `parseActionCommand`
2. **act/container**: `sanitizeConfig` and `mergeContainerConfigs` stop returning the configs they already mutate in place, drop never-set option fields and the unused `user` parameter of `ExecWithCmdLine`
3. **act/common and cache server**: drop the unused `Trace`/`Tracef` loggers and the short SHA of `FindGitRevision`, `RegisterJob` releases through `RevokeJob`
4. **daemon, poller and reporter**: one shutdown wait for both poll modes, drop an unreachable fetch timeout branch, guard the reporter's last report time with its existing lock instead of an atomic
5. **build**: drop unused Makefile and release workflow variables, collapse the goreleaser ignore list to the same build targets
6. **tests**: fold near-duplicate tests into tables with shared setup

Throughout, hand-rolled logic gives way to `cmp.Or`, `strings.Cut`, `slices` and `min`/`max`.

Reviewed-on: https://gitea.com/gitea/runner/pulls/1335
Reviewed-by: bircni <[email protected]>
Co-authored-by: silverwind <[email protected]>

.gitea/workflows/release-nightly.yml

@@ -11,7 +11,6 @@ on:
 
 env:
   DOCKER_ORG: gitea
-  DOCKER_LATEST: nightly
 
 jobs:
   goreleaser:

.gitea/workflows/release-tag.yml

@@ -69,7 +69,6 @@ jobs:
       image: catthehacker/ubuntu:act-latest
     env:
       DOCKER_ORG: gitea
-      DOCKER_LATEST: latest
     steps:
       - name: Checkout
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7