Bug 1545810 - disable tests in testing/web-platform/meta/media-source/ on windows10-aarch64 that cause task to abort r=jmaher

Changes:
- disable wholesale the `media-source` subsuite within web-platform-test

Attempts were made to isolate the tests that cause the test harness to lock up with a permission issue on `Ahem.ttf` however the attempts were unsuccessful in isolating the tests to a manageable set. It appears the solution is to simply stop running `media-source` tests on windows10-aarch64 as that seems to have solved the problem in a previous try run.

Differential Revision: https://phabricator.services.mozilla.com/D28778

--HG--
extra : moz-landing-system : lando

taskcluster/ci/test/test-sets.yml

@@ -270,7 +270,7 @@ windows-aarch64-tests:
     - mochitest-webgl2-core
     - mochitest-webgl2-ext
     - reftest
-    # - web-platform-tests - disabled due to wpt11 experiencing BSoD
+    - web-platform-tests
     - web-platform-tests-reftests
     - xpcshell
 

testing/web-platform/meta/media-source/__dir__.ini

@@ -1,2 +1,4 @@
 prefs: [media.mediasource.experimental.enabled:true]
 leak-threshold: [default: 51200]
+disabled:
+    if (os == "win") and (processor == "aarch64"): https://bugzilla.mozilla.org/show_bug.cgi?id=1545810