chore: still keep ctx in git.Repository struct for cat-file batch command (#38684)

Unfortunately, we can't completely remove the ctx from git.Repository,
because the CatFileBatch still heavily depends on a parent context.

If we remove the Repository ctx, the CatFileBatch will become a mess and
create a lot of unnecessary git processes.

http://localhost:3000/-/admin/monitor/perftrace

* Before: open a repo home, dozens of git processes (duplicate cat-file)
* After: only a few (no duplicate cat-file)

services/actions/commit_status_test.go

@@ -47,7 +47,7 @@ func TestCreateCommitStatus_Dedupe(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
 
 	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 4})
-	gitRepo, err := git.OpenRepository(repo)
+	gitRepo, err := git.OpenRepository(t.Context(), repo)
 	require.NoError(t, err)
 	defer gitRepo.Close()
 

services/actions/notifier_helper.go

@@ -147,7 +147,7 @@ func notify(ctx context.Context, input *notifyInput) error {
 		return nil
 	}
 
-	gitRepo, err := git.OpenRepository(input.Repo)
+	gitRepo, err := git.OpenRepository(ctx, input.Repo)
 	if err != nil {
 		return fmt.Errorf("git.OpenRepository: %w", err)
 	}
@@ -590,7 +590,7 @@ func DetectAndHandleSchedules(ctx context.Context, repo *repo_model.Repository)
 		return nil
 	}
 
-	gitRepo, err := git.OpenRepository(repo)
+	gitRepo, err := git.OpenRepository(ctx, repo)
 	if err != nil {
 		return fmt.Errorf("git.OpenRepository: %w", err)
 	}

services/actions/reusable_workflow.go

@@ -94,7 +94,7 @@ func loadReusableWorkflowSource(ctx context.Context, run *actions_model.ActionRu
 
 // readWorkflowFromRepo loads a workflow file from `repo` at `refOrSHA` and returns its content plus the resolved commit SHA.
 func readWorkflowFromRepo(ctx context.Context, repo *repo_model.Repository, refOrSHA, path string) ([]byte, string, error) {
-	gitRepo, err := git.OpenRepository(repo)
+	gitRepo, err := git.OpenRepository(ctx, repo)
 	if err != nil {
 		return nil, "", fmt.Errorf("open repo %s: %w", repo.FullName(), err)
 	}

services/actions/scoped_workflow_cache.go

@@ -50,7 +50,7 @@ func LoadParsedScopedWorkflows(ctx context.Context, sourceRepo *repo_model.Repos
 	}
 
 	// cache miss: open the source repo at the exact SHA we keyed on
-	sourceGitRepo, err := git.OpenRepository(sourceRepo)
+	sourceGitRepo, err := git.OpenRepository(ctx, sourceRepo)
 	if err != nil {
 		return "", nil, fmt.Errorf("open source repo: %w", err)
 	}