featureFilter: $type filter does not match Multi* geometries

[MikkoSteerpath]

Describe the bug
According to the spec, a filter like `["==", "$type", "Polygon"] should match both "MultiPolygon" and "Polygon" geometries. However when using featureFilter() api, this is not the case.

To Reproduce
Jest test case:

import { featureFilter, LegacyFilterSpecification } from '@maplibre/maplibre-gl-style-spec';

test('$type == "Polygon" should match Polygon and MultiPolygon features', () => {
  const typeFilterPoly: LegacyFilterSpecification = ['==', '$type', 'Polygon'];

  const { filter: matchesPolygon } = featureFilter(typeFilterPoly);
  expect(matchesPolygon({ zoom: 14 }, { type: 'Polygon', properties: {} })).toBe(true);
  expect(matchesPolygon({ zoom: 14 }, { type: 'LineString', properties: {} })).toBe(false);
  // This one fails currently: 
  expect(matchesPolygon({ zoom: 14 }, { type: 'MultiPolygon', properties: {} })).toBe(true);
});

Expected behavior
Tests should pass, including the last one.

Desktop (please complete the following information):
tested with version 24.3.0

Additional context
Discussed briefly with Harel Mazor in slack.