Add more macOS builders (#3485)

* 👷 add more macOS builders

* 👷 add more macOS builders

* 💚 fix macOS build

* 📝 document new Xcode versions

.github/workflows/macos.yml

@@ -10,7 +10,7 @@ on:
   workflow_dispatch:
 
 jobs:
-  xcode:
+  xcode_1:
     runs-on: macos-10.15
     strategy:
       matrix:
@@ -27,8 +27,25 @@ jobs:
       - name: test
         run: cd build ; ctest -j 10 --output-on-failure
 
+  xcode_2:
+    runs-on: macos-12
+    strategy:
+      matrix:
+        xcode: [13.3.1, 13.3, 13.2.1, 13.2, 13.1]
+    env:
+      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: cmake
+        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
+      - name: build
+        run: cmake --build build --parallel 10
+      - name: test
+        run: cd build ; ctest -j 10 --output-on-failure
+
   xcode_standards:
-    runs-on: macos-10.15
+    runs-on: macos-latest
     strategy:
       matrix:
         standard: [11, 14, 17, 20]