Drop temporary index on vulnerability_occurrences

Introduced in
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/49937
to speed up the deduplication process.

Changelog: changed

db/migrate/20220119170426_remove_temporary_vulnerability_occurrences_deduplication_index.rb

+# frozen_string_literal: true
+
+class RemoveTemporaryVulnerabilityOccurrencesDeduplicationIndex < Gitlab::Database::Migration[1.0]
+  MIGRATION = 'RecalculateVulnerabilitiesOccurrencesUuid'
+  INDEX_NAME = 'tmp_idx_deduplicate_vulnerability_occurrences'
+
+  disable_ddl_transaction!
+
+  def up
+    finalize_background_migration(MIGRATION)
+
+    remove_concurrent_index_by_name(:vulnerability_occurrences, INDEX_NAME)
+  end
+
+  def down
+    add_concurrent_index :vulnerability_occurrences,
+      %i[project_id report_type location_fingerprint primary_identifier_id id],
+      name: INDEX_NAME
+  end
+end

db/schema_migrations/20220119170426

+a488fecd8e6e99b8d32ac27f72c6a3575b0ed29baaf242133e5d1abbd5b64314
\ No newline at end of file

db/structure.sql

@@ -28346,8 +28346,6 @@ CREATE UNIQUE INDEX term_agreements_unique_index ON term_agreements USING btree
 
 CREATE INDEX tmp_gitlab_subscriptions_max_seats_used_migration ON gitlab_subscriptions USING btree (id) WHERE ((start_date >= '2021-08-02'::date) AND (start_date <= '2021-11-20'::date) AND (max_seats_used <> 0) AND (max_seats_used > seats_in_use) AND (max_seats_used > seats));
 
-CREATE INDEX tmp_idx_deduplicate_vulnerability_occurrences ON vulnerability_occurrences USING btree (project_id, report_type, location_fingerprint, primary_identifier_id, id);
-
 CREATE INDEX tmp_idx_vulnerability_occurrences_on_id_where_report_type_7_99 ON vulnerability_occurrences USING btree (id) WHERE (report_type = ANY (ARRAY[7, 99]));
 
 CREATE INDEX tmp_index_container_repositories_on_id_migration_state ON container_repositories USING btree (id, migration_state);

ee/spec/models/vulnerabilities/finding_spec.rb

@@ -7,7 +7,7 @@ RSpec.describe Vulnerabilities::Finding do
   it { is_expected.to define_enum_for(:severity) }
   it { is_expected.to define_enum_for(:detection_method) }
 
-  it { is_expected.to have_locked_schema('f17b760f30a3ad4e9c7a0d8580161649e7f3c9fd2b4a7e566884be41112468fe').reference('https://gitlab.com/gitlab-org/gitlab/-/issues/349315') }
+  it { is_expected.to have_locked_schema('9365b96bf5968b685f28c7c41659aa384e7d0c019cfeb244f22bb6d4bb49cdd7').reference('https://gitlab.com/gitlab-org/gitlab/-/issues/349315') }
 
   where(vulnerability_finding_signatures: [true, false])
   with_them do