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.go

@@ -5,6 +5,7 @@ package repository
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	actions_model "gitea.dev/models/actions"
@@ -48,9 +49,11 @@ func deleteDBRepository(ctx context.Context, repoID int64) error {
 	return nil
 }
 
-// DeleteRepository deletes a repository for a user or organization.
-// make sure if you call this func to close open sessions (sqlite will otherwise get a deadlock)
+// DeleteRepositoryDirectly deletes a repository for a user or organization.
 func DeleteRepositoryDirectly(ctx context.Context, repoID int64, ignoreOrgTeams ...bool) error {
+	if db.InTransaction(ctx) {
+		return errors.New("DeleteRepositoryDirectly must not be called within a transaction, it deletes storage once its own transaction commits")
+	}
 	ctx, committer, err := db.TxContext(ctx)
 	if err != nil {
 		return err