test: speed up tests, fix transaction bug (#39030)

Speed up tests: `make test-backend` 103s to 37s, `make test-integration`
908s to 852s.

Most of it is a detached system notice insert blocking on the SQLite
write lock until the busy timeout expired, and `ExternalServiceHTTP`
re-probing on every call with an untimed `http.Get`.

- fixed one correctness bug with nested transactions: files were deleted
while the outer transaction was open, so a later failure could roll the
database back with the files gone
- git push branch counts were far above the hook batch size
- Fix makefile dependencies so running tests and lint work in fresh
worktrees.

---------

Co-authored-by: Giteabot <teabot@gitea.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

services/repository/delete_test.go

@@ -4,6 +4,7 @@
 package repository_test
 
 import (
+	"context"
 	"testing"
 
 	actions_model "gitea.dev/models/actions"
@@ -54,6 +55,16 @@ func TestDeleteOwnerRepositoriesDirectly(t *testing.T) {
 	user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
 
 	assert.NoError(t, repo_service.DeleteOwnerRepositoriesDirectly(t.Context(), user))
+
+	t.Run("RejectedInTransaction", func(t *testing.T) {
+		unittest.PrepareTestEnv(t)
+
+		err := db.WithTx(t.Context(), func(ctx context.Context) error {
+			return repo_service.DeleteRepositoryDirectly(ctx, 1)
+		})
+		assert.ErrorContains(t, err, "must not be called within a transaction")
+		unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+	})
 }
 
 func TestDeleteRepositoryDirectlyPurgesRepoScopedRows(t *testing.T) {