Migrate to macOS 15 x86_64 for release build (#21)

* Migrate to macOS 15 x86_64 for release build

Because macOS 13 image is deprecated, see https://redirect.github.com/actions/runner-images/issues/13046

Also adjusts the build setup a bit to make it easier to understand.

* Rename matrix variable

Author: Marcono1234

.github/workflows/build-all-and-publish.yml

@@ -95,12 +95,13 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - os: macos-13
+          - os: macos-15-intel
             arch: x86_64
-            java7: true
+            fullbuild: true
           - os: macos-14
             arch: aarch64
-            java7: false
+            # Build only the native binary for this architecture; it suffices if only one of the macOS builds performs a full Maven build
+            fullbuild: false
 
     steps:
       - name: Checkout
@@ -111,7 +112,7 @@ jobs:
 
       - name: Setup Zulu JDK 7
         uses: actions/setup-java@v5
-        if: ${{ matrix.java7 }}
+        if: ${{ matrix.fullbuild }}
         with:
           distribution: zulu
           java-version: '7'
@@ -122,16 +123,16 @@ jobs:
           java-version: '21'
           cache: maven
 
-      - name: Build (process-resources only on macos-14)
-        if: ${{ matrix.os == 'macos-14' }}
+      - name: Build (native binary build only)
+        if: ${{ !matrix.fullbuild }}
         run: |
           ./mvnw -B -V -DskipTests \
             -Darch.id=${{ matrix.arch }} \
             -Dnative.cc=cc \
             process-resources
 
-      - name: Build (mvn verify on macos-13)
-        if: ${{ matrix.os != 'macos-14' }}
+      - name: Build (full build)
+        if: ${{ matrix.fullbuild }}
         run: |
           ./mvnw -B -V \
             -Darch.id=${{ matrix.arch }} \