Improve branch select list ui in go templates (#29729)

Relate:[#27417](https://github.com/go-gitea/gitea/issues/27471)
Reference:  [#26631](https://github.com/go-gitea/gitea/pull/26631)

Before


![image](https://github.com/go-gitea/gitea/assets/37935145/88ca8da5-25dd-4f60-bea8-a80107f19cc5)

After


![image](https://github.com/go-gitea/gitea/assets/37935145/3cb180dc-1331-43e9-8633-be5e288401e8)

---------

Co-authored-by: silverwind <me@silverwind.io>

templates/repo/branch_dropdown.tmpl

@@ -56,7 +56,7 @@
 		'repoLink': {{.root.RepoLink}},
 		'treePath': {{.root.TreePath}},
 		'branchNameSubURL': {{.root.BranchNameSubURL}},
-		'noResults': {{ctx.Locale.Tr "repo.pulls.no_results"}},
+		'noResults': {{ctx.Locale.Tr "no_results_found"}},
 	};
 	{{if .release}}
 	data.release = {