Set the Mac GHA runners to 13 instead of latest (#686)

* Pin GHA workflows to macos-13

* Force the GHA runners to use Java 8

Author: a-maurice

.github/workflows/build_macos.yaml

@@ -33,7 +33,7 @@ env:
 jobs:
   build_desktop:
     name: build-macOS-unity${{ inputs.unity_version}}
-    runs-on: macos-latest
+    runs-on: macos-13
     strategy:
       fail-fast: false
 
@@ -55,6 +55,10 @@ jobs:
         shell: bash
         run: echo "UNITY_EXE=${{ env.UNITY_ROOT_DIR }}/Unity.app/Contents/MacOS/Unity" >> $GITHUB_ENV
 
+      - name: Force Java 8
+        shell: bash
+        run: echo "JAVA_HOME=${JAVA_HOME_8_X64}" >> $GITHUB_ENV
+
       # Build .unitypackage
       - run: ./gradlew buildPlugin --info
 

.github/workflows/test.yaml

@@ -107,7 +107,7 @@ jobs:
 
   test_on_macos:
     name: test-macOS-unity${{ needs.check_and_prepare.outputs.unity_version }}
-    runs-on: macos-latest
+    runs-on: macos-13
     needs: [check_and_prepare]
     strategy:
       fail-fast: false
@@ -128,6 +128,10 @@ jobs:
         shell: bash
         run: echo "UNITY_EXE=${{ env.UNITY_ROOT_DIR }}/Unity.app/Contents/MacOS/Unity" >> $GITHUB_ENV
 
+      - name: Force Java 8
+        shell: bash
+        run: echo "JAVA_HOME=${JAVA_HOME_8_X64}" >> $GITHUB_ENV
+
       - name: Run tests
         shell: bash
         timeout-minutes: 60