ref: use an explicit primary key for social_auth model (#53350)

this was the implicit default value before -- django 3.2 makes it warn,
django 4 makes it an error

social_auth seems to be the only one receiving this default value as we
set `id = BoundedBigAutoField(primary_key=True)` in our base model

migrations_lockfile.txt

@@ -7,4 +7,4 @@ will then be regenerated, and you should be able to merge without conflicts.
 
 nodestore: 0002_nodestore_no_dictfield
 sentry: 0516_switch_pagerduty_silo
-social_auth: 0001_initial
+social_auth: 0002_default_auto_field

src/social_auth/migrations/0002_default_auto_field.py

@@ -0,0 +1,31 @@
+# Generated by Django 3.2.20 on 2023-07-21 18:31
+
+from django.db import migrations, models
+
+from sentry.new_migrations.migrations import CheckedMigration
+
+
+class Migration(CheckedMigration):
+    # This flag is used to mark that a migration shouldn't be automatically run in production. For
+    # the most part, this should only be used for operations where it's safe to run the migration
+    # after your code has deployed. So this should not be used for most operations that alter the
+    # schema of a table.
+    # Here are some things that make sense to mark as dangerous:
+    # - Large data migrations. Typically we want these to be run manually by ops so that they can
+    #   be monitored and not block the deploy for a long period of time while they run.
+    # - Adding indexes to large tables. Since this can take a long time, we'd generally prefer to
+    #   have ops run this and not block the deploy. Note that while adding an index is a schema
+    #   change, it's completely safe to run the operation after the code has deployed.
+    is_dangerous = False
+
+    dependencies = [
+        ("social_auth", "0001_initial"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="usersocialauth",
+            name="id",
+            field=models.AutoField(primary_key=True, serialize=False),
+        ),
+    ]

src/social_auth/models.py

@@ -25,6 +25,7 @@ CLEAN_USERNAME_REGEX = re.compile(r"[^\w.@+-_]+", re.UNICODE)
 class UserSocialAuth(models.Model):
     """Social Auth association model"""
 
+    id = models.AutoField(primary_key=True)
     user = models.ForeignKey(AUTH_USER_MODEL, related_name="social_auth", on_delete=models.CASCADE)
     provider = models.CharField(max_length=32)
     uid = models.CharField(max_length=UID_LENGTH)