Use repo as of renderctx's member rather than a repoPath on metas (#29222)

Use a `gitrepo.Repository` in the markup's RenderContext but not store
the repository's path.

modules/gitrepo/url.go

@@ -0,0 +1,8 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package gitrepo
+
+func RepoGitURL(repo Repository) string {
+	return repoPath(repo)
+}