HashGroupingOperator has been updated to close inbound pages. Ordinals needs to do similar.
x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/OperatorTests.java
/**
     * Creates a {@link BigArrays} that tracks releases but doesn't throw circuit breaking exceptions.
     */
    private BigArrays bigArrays() {
        return new MockBigArrays(new MockPageCacheRecycler(Settings.EMPTY), new NoneCircuitBreakerService());
    }
    /**
     * A {@link DriverContext} that won't throw {@link CircuitBreakingException}.
     */
    protected final DriverContext driverContext() {
        var breaker = new MockBigArrays.LimitedBreaker("esql-test-breaker", ByteSizeValue.ofGb(1));
        return new DriverContext(bigArrays(), BlockFactory.getInstance(breaker, bigArrays()));
    }
    public static void assertDriverContext(DriverContext driverContext) {
        assertTrue(driverContext.isFinished());
        assertThat(driverContext.getSnapshot().releasables(), empty());
    }
    static LuceneOperator.Factory luceneOperatorFactory(IndexReader reader, Query query, int limit) {
        final SearchContext searchContext = mockSearchContext(reader);
        return new LuceneSourceOperator.Factory(
            List.of(searchContext),
            ctx -> query,
            randomFrom(DataPartitioning.values()),
            randomIntBetween(1, 10),
            randomPageSize(),
            limit
        );
    }
}