Add unit tests for action runner token (#27670)

In case the behavior of the register token changes.

models/actions/main_test.go

@@ -0,0 +1,18 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package actions
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/unittest"
+)
+
+func TestMain(m *testing.M) {
+	unittest.MainTest(m, &unittest.TestOptions{
+		FixtureFiles: []string{
+			"action_runner_token.yml",
+		},
+	})
+}