More db.DefaultContext refactor (#27265)

Part of #27065

This PR touches functions used in templates. As templates are not static
typed, errors are harder to find, but I hope I catch it all. I think
some tests from other persons do not hurt.

routers/web/repo/setting/setting.go

@@ -695,7 +695,7 @@ func SettingsPost(ctx *context.Context) {
 		if _, err := repo_module.CleanUpMigrateInfo(ctx, repo); err != nil {
 			ctx.ServerError("CleanUpMigrateInfo", err)
 			return
-		} else if err = repo_model.DeleteMirrorByRepoID(ctx.Repo.Repository.ID); err != nil {
+		} else if err = repo_model.DeleteMirrorByRepoID(ctx, ctx.Repo.Repository.ID); err != nil {
 			ctx.ServerError("DeleteMirrorByRepoID", err)
 			return
 		}