Add EmailMultiAlternatives.body_contains() (#2618)

* Add EmailMultiAlternatives.body_contains()

docs: https://docs.djangoproject.com/en/5.2/topics/email/#django.core.mail.EmailMultiAlternatives.body_contains

* Remove the corresponding allowlist entries

Author: cuu508

django-stubs/core/mail/message.pyi

@@ -108,3 +108,4 @@ class EmailMultiAlternatives(EmailMessage):
         reply_to: Sequence[str] | None = None,
     ) -> None: ...
     def attach_alternative(self, content: _AttachmentContent, mimetype: str) -> None: ...
+    def body_contains(self, text: str) -> bool: ...

scripts/stubtest/allowlist_todo_django52.txt

@@ -82,10 +82,8 @@ django.core.handlers.wsgi.LimitedStream.read
 django.core.handlers.wsgi.LimitedStream.readline
 django.core.mail.EmailAlternative
 django.core.mail.EmailAttachment
-django.core.mail.EmailMultiAlternatives.body_contains
 django.core.mail.message.EmailAlternative
 django.core.mail.message.EmailAttachment
-django.core.mail.message.EmailMultiAlternatives.body_contains
 django.core.management.commands.shell.Command.get_auto_imports
 django.core.management.commands.shell.Command.get_namespace
 django.core.management.utils.run_formatters