Update macOS versions to use for testing. (#916)

.github/workflows/ci.yaml

@@ -21,12 +21,27 @@ jobs:
         go: ['1.22', '1.23', 'tip']
         # Supported macOS versions can be found in
         # https://github.com/actions/virtual-environments#available-environments.
-        # TODO: Add macos-13. As of now there are build errors when installing graphviz.
-        os: ['macos-12']
+        os: ['macos-13', 'macos-14']
         # Supported Xcode versions can be found in:
-        # - https://github.com/actions/virtual-environments/blob/main/images/macos/macos-12-Readme.md#xcode
         # - https://github.com/actions/virtual-environments/blob/main/images/macos/macos-13-Readme.md#xcode
-        xcode-version: ['14.2', '14.1', '14.0.1', '13.4.1', '13.3.1', '13.2.1', '13.1']
+        # - https://github.com/actions/virtual-environments/blob/main/images/macos/macos-14-Readme.md#xcode
+        xcode-version: ['16.1', '16.0', '15.4', '15.3', '15.2', '15.1', '15.0.1', '14.3.1', '14.2', '14.1']
+        exclude:
+          - os: 'macos-13'
+            xcode-version: '16.1'
+          - os: 'macos-13'
+            xcode-version: '16.0'
+          - os: 'macos-13'
+            xcode-version: '15.4'
+          - os: 'macos-13'
+            xcode-version: '15.3'
+          - os: 'macos-14'
+            xcode-version: '14.3.1'
+          - os: 'macos-14'
+            xcode-version: '14.2'
+          - os: 'macos-14'
+            xcode-version: '14.1'
+
     steps:
       - name: Checkout the repo
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2