Fix macOS Intel runner image

Author: charphi

.github/workflows/java8-maven.yml

@@ -12,7 +12,7 @@ jobs:
       fail-fast: false
       matrix:
         java: [ 17, 21 ]
-        os: [ ubuntu-latest, macos-13, windows-latest ]
+        os: [ ubuntu-latest, macos-15-intel, windows-latest ]
 
     name: JDK${{ matrix.java }} on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}