Add timestamptz to the data types list

"Column ordering suggestions" is suggesting an incorrect order in gitlab-org/gitlab!108908 (merged) because timestamptz (8 bytes) is not listed in pg_data_types.yml.

Given the following statement:

CREATE TABLE IF NOT EXISTS "namespace_ldap_settings" (
"namespace_id" bigint NOT NULL PRIMARY KEY,
"created_at" timestamptz NOT NULL,
"updated_at" timestamptz NOT NULL,
"sync_last_start_at" timestamptz,
"sync_last_update_at" timestamptz,
"sync_last_successful_at" timestamptz,
"sync_status" smallint DEFAULT 0 NOT NULL,
"sync_error" text,
CONSTRAINT "fk_rails_82cd0ad4bb" FOREIGN KEY ("namespace_id") REFERENCES "namespaces" ("id") ON DELETE CASCADE,
CONSTRAINT check_51a03d26b6 CHECK (char_length("sync_error") <= 255)
)

The currently suggested order is:

Column name	Data Type
namespace_id	int8
sync_status	int2
created_at	timestamptz
updated_at	timestamptz
sync_last_start_at	timestamptz
sync_last_update_at	timestamptz
sync_last_successful_at	timestamptz
sync_error	text