ref(externaluser): Drop ExternalUser and ExternalTeam tables (#25827)

* ref(externaluser): Drop ExternalUser and ExternalTeam tables

migrations_lockfile.txt

@@ -7,5 +7,5 @@ will then be regenerated, and you should be able to merge without conflicts.
 
 jira_ac: 0001_initial
 nodestore: 0002_nodestore_no_dictfield
-sentry: 0189_remove_externaluser_externalteam_models
+sentry: 0190_drop_external_user_table
 social_auth: 0001_initial

src/sentry/migrations/0190_drop_external_user_table.py

@@ -0,0 +1,44 @@
+# Generated by Django 1.11.29 on 2021-05-03 21:05
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    # This flag is used to mark that a migration shouldn't be automatically run in
+    # production. We set this to True for operations that we think are risky and want
+    # someone from ops to run manually and monitor.
+    # General advice is that if in doubt, mark your migration as `is_dangerous`.
+    # Some things you should always mark as dangerous:
+    # - Large data migrations. Typically we want these to be run manually by ops so that
+    #   they can be monitored. Since data migrations will now hold a transaction open
+    #   this is even more important.
+    # - Adding columns to highly active tables, even ones that are NULL.
+    is_dangerous = False
+
+    # This flag is used to decide whether to run this migration in a transaction or not.
+    # By default we prefer to run in a transaction, but for migrations where you want
+    # to `CREATE INDEX CONCURRENTLY` this needs to be set to False. Typically you'll
+    # want to create an index concurrently when adding one to an existing table.
+    # You'll also usually want to set this to `False` if you're writing a data
+    # migration, since we don't want the entire migration to run in one long-running
+    # transaction.
+    atomic = True
+
+    dependencies = [
+        ("sentry", "0189_remove_externaluser_externalteam_models"),
+    ]
+
+    operations = [
+        migrations.RunSQL(
+            """
+                DROP TABLE "sentry_externaluser";
+                """,
+            reverse_sql="CREATE TABLE sentry_externaluser (fake_col int)",  # We just create a fake table here so that the DROP will work if we roll back the migration.
+        ),
+        migrations.RunSQL(
+            """
+                DROP TABLE "sentry_externalteam";
+                """,
+            reverse_sql="CREATE TABLE sentry_externalteam (fake_col int)",  # We just create a fake table here so that the DROP will work if we roll back the migration.
+        ),
+    ]