Avoid too long names for actions (#23162)

The name of the job or step comes from the workflow file, while the name
of the runner comes from its registration. If the strings used for these
names are too long, they could cause db issues.

routers/api/actions/runner/runner.go

@@ -12,6 +12,7 @@ import (
 	"code.gitea.io/gitea/modules/actions"
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/util"
 	actions_service "code.gitea.io/gitea/services/actions"
 
 	runnerv1 "code.gitea.io/actions-proto-go/runner/v1"
@@ -55,9 +56,10 @@ func (s *Service) Register(
 	}
 
 	// create new runner
+	name, _ := util.SplitStringAtByteN(req.Msg.Name, 255)
 	runner := &actions_model.ActionRunner{
 		UUID:         gouuid.New().String(),
-		Name:         req.Msg.Name,
+		Name:         name,
 		OwnerID:      runnerToken.OwnerID,
 		RepoID:       runnerToken.RepoID,
 		AgentLabels:  req.Msg.AgentLabels,