Enable WOFF2 WPT tests

• Component: CSS
• Status: RESOLVED CONFIGURATION CHANGED

[Frédéric Wang (:fredw)]

WOFF2 WPT tests were imported in bug 179108 but only enabled on the GTK port for now.

@Myles: For the record, the success rate on the macOS port is ~86%:

264 tests ran as expected, 37 didn't:

Unexpected flakiness:
  blocks-extraneous-data-001.xht
  header-signature-001.xht
Regressions: Unexpected
  blocks-extraneous-data-002.xht
  blocks-extraneous-data-003.xht
  blocks-extraneous-data-004.xht
  blocks-extraneous-data-005.xht
  blocks-extraneous-data-006.xht
  blocks-extraneous-data-007.xht
  blocks-extraneous-data-008.xht
  blocks-overlap-001.xht
  blocks-overlap-002.xht
  blocks-overlap-003.xht
  datatypes-invalid-base128-001.xht
  datatypes-invalid-base128-002.xht
  datatypes-invalid-base128-003.xht
  directory-mismatched-tables-001.xht
  header-length-001.xht
  header-length-002.xht
  header-numTables-001.xht
  tabledata-bad-origlength-loca-001.xht
  tabledata-bad-origlength-loca-002.xht
  tabledata-brotli-001.xht
  tabledata-decompressed-length-001.xht
  tabledata-decompressed-length-002.xht
  tabledata-decompressed-length-003.xht
  tabledata-decompressed-length-004.xht
  tabledata-extraneous-data-001.xht
  tabledata-glyf-bbox-001.xht
  tabledata-glyf-bbox-002.xht
  tabledata-glyf-bbox-003.xht
  tabledata-glyf-origlength-001.xht
  tabledata-glyf-origlength-002.xht
  tabledata-non-zero-loca-001.xht
  tabledata-transform-bad-flag-001.xht
  tabledata-transform-bad-flag-002.xht
  tabledata-transform-hmtx-003.xht
  tabledata-transform-hmtx-004.xht

[Alicia Boya García]

r232903 imported new failing tests (ImageOnlyFailure):

imported/w3c/web-platform-tests/css/WOFF2/directory-knowntags-001.xht
imported/w3c/web-platform-tests/css/WOFF2/tabledata-glyf-origlength-003.xht