management: Add lockfiles to all _once management jobs.

These would be bad if more than once ran at once.

zilencer/management/commands/calculate_first_visible_message_id.py

@@ -3,7 +3,7 @@ from typing import Any, Iterable
 from django.core.management.base import CommandParser
 from typing_extensions import override
 
-from zerver.lib.management import ZulipBaseCommand
+from zerver.lib.management import ZulipBaseCommand, abort_unless_locked
 from zerver.lib.message import maybe_update_first_visible_message_id
 from zerver.models import Realm
 
@@ -23,6 +23,7 @@ class Command(ZulipBaseCommand):
         )
 
     @override
+    @abort_unless_locked
     def handle(self, *args: Any, **options: Any) -> None:
         target_realm = self.get_realm(options)