Add e2e debug server

This adds the ability to run `make test-e2e-debugserver` to start a
forgejo server pupulated with the test data from `models/fixtures`. This
is particularly useful for debugging the e2e tests with a external tool,
such as the Playwright extension for VSCode [1].

[1] https://open-vsx.org/extension/ms-playwright/playwright

tests/e2e/debugserver_test.go

@@ -0,0 +1,30 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+// This "test" is meant to be run with `make test-e2e-debugserver` and will just
+// keep open a gitea instance in a test environment (with the data from
+// `models/fixtures`) on port 3000. This is useful for debugging e2e tests, for
+// example with the playwright vscode extension.
+
+//nolint:forbidigo
+package e2e
+
+import (
+	"net/url"
+	"os"
+	"os/signal"
+	"syscall"
+	"testing"
+
+	"code.gitea.io/gitea/modules/setting"
+)
+
+func TestDebugserver(t *testing.T) {
+	done := make(chan os.Signal, 1)
+	signal.Notify(done, syscall.SIGINT, syscall.SIGTERM)
+
+	onGiteaRun(t, func(*testing.T, *url.URL) {
+		println(setting.AppURL)
+		<-done
+	})
+}