Migrate to macos-15-intel github action image

The macos-13 image will be removed soon and macos-14-(x)large / x86_64 is not availble for free:
https://github.blog/changelog/2025-09-19-github-actions-macos-13-runner-image-is-closing-down/

Author: carstene1ns

.github/workflows/build.yml

@@ -354,9 +354,9 @@ jobs:
           name: "tic80-nintendo-3ds"
           path: build/bin/tic80.3dsx
 
-  # === MacOS 13 ===
-  macos:
-    runs-on: macos-13
+  # === MacOS 14 / arm64 ===
+  macos-arm64:
+    runs-on: macos-14
 
     steps:
       - uses: actions/checkout@v4
@@ -376,7 +376,7 @@ jobs:
       - name: Deploy
         uses: actions/upload-artifact@v4
         with:
-          name: "tic80-macos"
+          name: "tic80-macos-arm64"
           path: |
             build/bin/tic80
             build/bin/*.dylib
@@ -387,9 +387,9 @@ jobs:
           cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_SDLGPU=On -DBUILD_PRO=On -DBUILD_WITH_ALL=ON -DCMAKE_POLICY_VERSION_MINIMUM=3.5 ..
           cmake --build . --parallel
 
-  # === MacOS 14 / arm64 ===
-  macos-arm64:
-    runs-on: macos-14
+  # === MacOS 15 / x86_64 ===
+  macos:
+    runs-on: macos-15-intel
 
     steps:
       - uses: actions/checkout@v4
@@ -409,15 +409,15 @@ jobs:
       - name: Deploy
         uses: actions/upload-artifact@v4
         with:
-          name: "tic80-macos-arm64"
+          name: "tic80-macos"
           path: |
             build/bin/tic80
             build/bin/*.dylib
 
       - name: Build Pro
         run: |
           cd build
-          cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_SDLGPU=On -DBUILD_PRO=On -DBUILD_WITH_ALL=ON ..
+          cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_SDLGPU=On -DBUILD_PRO=On -DBUILD_WITH_ALL=ON -DCMAKE_POLICY_VERSION_MINIMUM=3.5 ..
           cmake --build . --parallel
 
   # === Android ===