Drop project_id not null constraint ci_deleted_objects

This commit drops check_98f90d6c53 constraint to unblock the
accumulation of ci_job_artifacts that needs to be clean up from the
system.

Changelog: fixed

db/migrate/20241003073742_drop_not_null_to_ci_deleted_project_id.rb

+# frozen_string_literal: true
+
+class DropNotNullToCiDeletedProjectId < Gitlab::Database::Migration[2.2]
+  milestone '17.4'
+  disable_ddl_transaction!
+
+  TABLE_NAME = :ci_deleted_objects
+  COLUMN_NAME = :project_id
+
+  def up
+    remove_not_null_constraint(TABLE_NAME, COLUMN_NAME)
+  end
+
+  def down
+    add_not_null_constraint(TABLE_NAME, COLUMN_NAME, validate: false)
+  end
+end

db/schema_migrations/20241003073742

+7792d7833b32a800f3e3296e809487642411c354bc360b3ae580b22ce793fdb5
\ No newline at end of file

db/structure.sql

@@ -23411,9 +23411,6 @@ ALTER TABLE p_ci_pipeline_variables
 ALTER TABLE ci_runners
     ADD CONSTRAINT check_91230910ec CHECK ((char_length((name)::text) <= 256)) NOT VALID;
-ALTER TABLE ci_deleted_objects
-    ADD CONSTRAINT check_98f90d6c53 CHECK ((project_id IS NOT NULL)) NOT VALID;
-
 ALTER TABLE sprints
     ADD CONSTRAINT check_ccd8a1eae0 CHECK ((start_date IS NOT NULL)) NOT VALID;