Exclude Node 14 + macOS CI run.

.github/workflows/ci.yml

@@ -35,6 +35,18 @@ jobs:
       matrix:
         os: ['ubuntu', 'windows', 'macOS']
         node: ['6', '8', '10', '12', '14']
+        exclude:
+          # excludes node 14 on macOS, this is because
+          # ember-cli (until ~ 3.12) calls
+          # `fs.writeFileSync('./tmp/.metadata_never_index)` on macOS platforms
+          # to instruct spotlight to avoid indexing the local tmp folder
+          # unfortunately, ember-cli does not pass a value for second arg (the
+          # content to write) and Node 14 added an assertion
+          #
+          # TODO: delete this when we have dropped Node 6 and can update
+          # ember-cli to a version that doesn't do this
+          - os: 'macOS'
+            node: '14'
 
     steps:
     - uses: actions/checkout@v1