refactor(actions): small cleanups across models, services and routers (#39722)

Collection of small, behaviour-preserving cleanups in the Actions code.

- Fix log and error prefixes that named non-existent or wrong functions,
and wrap errors with `%w` so `errors.Is` keeps working.
- Remove unused code.
- Rely on `ctx.ServerError` / `ctx.APIErrorAuto`, which already map
`util.ErrNotExist` and friends, instead of equivalent hand-written
switches.
- Load runs referenced by commit statuses with one query instead of one
per run (used on every PR view); the result order is now stable.
- Encode an event's payload once instead of up to three times.
- Share the duplicated runner-token "get or create" logic and the
"notify and emit" call pair.
- Simplify `ToActionArtifact` / `ToActionRunner` signatures.

---------

Signed-off-by: bircni <bircni@icloud.com>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

models/actions/utils.go

@@ -89,22 +89,3 @@ func calculateDuration(started, stopped timeutil.TimeStamp, status Status, fallb
 	}
 	return max(timeSince(s), 0).Truncate(time.Second)
 }
-
-// best effort function to convert an action schedule to action run, to be used in GenerateGiteaContext
-func (s *ActionSchedule) ToActionRun() *ActionRun {
-	return &ActionRun{
-		Title:         s.Title,
-		RepoID:        s.RepoID,
-		Repo:          s.Repo,
-		OwnerID:       s.OwnerID,
-		WorkflowID:    s.WorkflowID,
-		TriggerUserID: s.TriggerUserID,
-		TriggerUser:   s.TriggerUser,
-		Ref:           s.Ref,
-		CommitSHA:     s.CommitSHA,
-		Event:         s.Event,
-		EventPayload:  s.EventPayload,
-		Created:       s.Created,
-		Updated:       s.Updated,
-	}
-}