Bug 1758780 - Increase test's fuzzTolerance to accomodate clang 14. r=padenot

Differential Revision: https://phabricator.services.mozilla.com/D143668

dom/media/webaudio/test/test_mediaDecoding.html

@@ -123,7 +123,7 @@ var files = [
     frames: 30592,
     sampleRate: 44100,
     duration: 0.693,
-    fuzzTolerance: 5,
+    fuzzTolerance: 6,
     fuzzToleranceMobile: 1284
   },
   // An ogg file, 44.1khz, stereo