Bug 1339604 - stylo builds + tests should only run on m-c and stylo branch to reduce budget impact r=kmoir a=merge

MozReview-Commit-ID: Lwph8g1ALVt

--HG--
extra : source : 4f8aecb0f44f4801e6c277077e788516e6dd31de
extra : amend_source : 2a26aa2b1904bc1058b41d75283c275570be5e66

taskcluster/ci/test/tests.yml

@@ -934,7 +934,8 @@ reftest-stylo:
     chunks: 16
     run-on-projects:
         by-test-platform:
-            linux64-stylo/.*: [ 'stylo', 'autoland', 'mozilla-inbound', 'mozilla-central' ]
+            linux64-stylo/opt: [ 'stylo', 'autoland', 'mozilla-central' ]
+            linux64-stylo/debug: [ 'stylo', 'autoland', 'mozilla-inbound', 'mozilla-central' ]
     e10s:
         by-test-platform:
             linux64-stylo/opt: