Use db.WithTx for AddTeamMember to avoid ctx abuse (#27095)

Compare with ignoring spaces:
https://github.com/go-gitea/gitea/pull/27095/files?diff=split&w=1

models/org_team.go

@@ -366,12 +366,7 @@ func AddTeamMember(ctx context.Context, team *organization.Team, userID int64) e
 		return err
 	}
 
-	ctx, committer, err := db.TxContext(ctx)
-	if err != nil {
-		return err
-	}
-	defer committer.Close()
-
+	err = db.WithTx(ctx, func(ctx context.Context) error {
 		// check in transaction
 		isAlreadyMember, err = organization.IsTeamMember(ctx, team.OrgID, team.ID, userID)
 		if err != nil || isAlreadyMember {
@@ -422,13 +417,18 @@ func AddTeamMember(ctx context.Context, team *organization.Team, userID int64) e
 				accesses = accesses[:0]
 			}
 		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
 
 	// this behaviour may spend much time so run it in a goroutine
 	// FIXME: Update watch repos batchly
 	if setting.Service.AutoWatchNewRepos {
 		// Get team and its repositories.
 		if err := team.LoadRepositories(ctx); err != nil {
-			log.Error("getRepositories failed: %v", err)
+			log.Error("team.LoadRepositories failed: %v", err)
 		}
 		// FIXME: in the goroutine, it can't access the "ctx", it could only use db.DefaultContext at the moment
 		go func(repos []*repo_model.Repository) {
@@ -440,7 +440,7 @@ func AddTeamMember(ctx context.Context, team *organization.Team, userID int64) e
 		}(team.Repos)
 	}
 
-	return committer.Commit()
+	return nil
 }
 
 func removeTeamMember(ctx context.Context, team *organization.Team, userID int64) error {