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>

routers/api/v1/shared/runners.go

@@ -4,14 +4,12 @@
 package shared
 
 import (
-	"errors"
 	"net/http"
 
 	actions_model "gitea.dev/models/actions"
 	"gitea.dev/models/db"
 	"gitea.dev/modules/setting"
 	api "gitea.dev/modules/structs"
-	"gitea.dev/modules/util"
 	"gitea.dev/modules/web"
 	"gitea.dev/routers/api/v1/utils"
 	"gitea.dev/services/context"
@@ -25,10 +23,7 @@ type RegistrationToken struct {
 }
 
 func GetRegistrationToken(ctx *context.APIContext, ownerID, repoID int64) {
-	token, err := actions_model.GetLatestRunnerToken(ctx, ownerID, repoID)
-	if errors.Is(err, util.ErrNotExist) || (token != nil && !token.IsActive) {
-		token, err = actions_model.NewRunnerToken(ctx, ownerID, repoID)
-	}
+	token, err := actions_model.GetOrCreateActiveRunnerToken(ctx, ownerID, repoID)
 	if err != nil {
 		ctx.APIErrorInternal(err)
 		return
@@ -64,7 +59,7 @@ func ListRunners(ctx *context.APIContext, ownerID, repoID int64) {
 
 	res.Entries = make([]*api.ActionRunner, len(runners))
 	for i, runner := range runners {
-		res.Entries[i] = convert.ToActionRunner(ctx, runner)
+		res.Entries[i] = convert.ToActionRunner(runner)
 	}
 
 	ctx.JSON(http.StatusOK, &res)
@@ -102,7 +97,7 @@ func GetRunner(ctx *context.APIContext, ownerID, repoID, runnerID int64) {
 	if !ok {
 		return
 	}
-	ctx.JSON(http.StatusOK, convert.ToActionRunner(ctx, runner))
+	ctx.JSON(http.StatusOK, convert.ToActionRunner(runner))
 }
 
 // DeleteRunner deletes the runner for api route validated ownerID and repoID