Add a doctor check to disable the "Actions" unit for mirrors (#32424)

Resolve #32232

Users can disable the "Actions" unit for all mirror repos by running 
```
gitea doctor check --run  disable-mirror-actions-unit --fix
```

services/doctor/actions.go

@@ -0,0 +1,70 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package doctor
+
+import (
+	"context"
+	"fmt"
+
+	"code.gitea.io/gitea/models/db"
+	repo_model "code.gitea.io/gitea/models/repo"
+	unit_model "code.gitea.io/gitea/models/unit"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/optional"
+	repo_service "code.gitea.io/gitea/services/repository"
+)
+
+func disableMirrorActionsUnit(ctx context.Context, logger log.Logger, autofix bool) error {
+	var reposToFix []*repo_model.Repository
+
+	for page := 1; ; page++ {
+		repos, _, err := repo_model.SearchRepository(ctx, &repo_model.SearchRepoOptions{
+			ListOptions: db.ListOptions{
+				PageSize: repo_model.RepositoryListDefaultPageSize,
+				Page:     page,
+			},
+			Mirror: optional.Some(true),
+		})
+		if err != nil {
+			return fmt.Errorf("SearchRepository: %w", err)
+		}
+		if len(repos) == 0 {
+			break
+		}
+
+		for _, repo := range repos {
+			if repo.UnitEnabled(ctx, unit_model.TypeActions) {
+				reposToFix = append(reposToFix, repo)
+			}
+		}
+	}
+
+	if len(reposToFix) == 0 {
+		logger.Info("Found no mirror with actions unit enabled")
+	} else {
+		logger.Warn("Found %d mirrors with actions unit enabled", len(reposToFix))
+	}
+	if !autofix || len(reposToFix) == 0 {
+		return nil
+	}
+
+	for _, repo := range reposToFix {
+		if err := repo_service.UpdateRepositoryUnits(ctx, repo, nil, []unit_model.Type{unit_model.TypeActions}); err != nil {
+			return err
+		}
+	}
+	logger.Info("Fixed %d mirrors with actions unit enabled", len(reposToFix))
+
+	return nil
+}
+
+func init() {
+	Register(&Check{
+		Title:     "Disable the actions unit for all mirrors",
+		Name:      "disable-mirror-actions-unit",
+		IsDefault: false,
+		Run:       disableMirrorActionsUnit,
+		Priority:  9,
+	})
+}