Move integration tests to tests/ directory (#973)

Reviewed-on: https://gitea.com/gitea/tea/pulls/973

modules/config/testtools.go

@@ -0,0 +1,13 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build testtools
+
+package config
+
+import "time"
+
+// AcquireConfigLockForTesting exposes the internal lock helper to integration tests.
+func AcquireConfigLockForTesting(lockPath string, timeout time.Duration) (func() error, error) {
+	return acquireConfigLock(lockPath, timeout)
+}