chore: rename act_runner references to runner (#38791)

The runner repository moved to https://gitea.com/gitea/runner, update references.

models/actions/runner.go

@@ -58,7 +58,7 @@ type ActionRunner struct {
 	LastOnline timeutil.TimeStamp `xorm:"index"`
 	LastActive timeutil.TimeStamp `xorm:"index"`
 
-	// Store labels defined in state file (default: .runner file) of `act_runner`
+	// Store labels defined in state file (default: .runner file) of the `runner`
 	AgentLabels []string `xorm:"TEXT"`
 	// Store if this is a runner that only ever get one single job assigned
 	Ephemeral bool `xorm:"ephemeral NOT NULL DEFAULT false"`