Try to improve the matrix and job names.

Author: dabrahams

.github/workflows/build-and-test.yml

@@ -165,25 +165,22 @@ jobs:
 
   native:
     needs: determine-version
-    name: "Native: ${{ matrix.os }}/${{ matrix.spm_configuration }}/${{ matrix.build_system }}/${{ matrix.cmake_generator }}"
+    name: "Native: ${{ matrix.os }}/${{ matrix.spm_configuration }}/${{ matrix.build_system }}${{ matrix.build_system == 'cmake' && format(':{0}', matrix.cmake_generator) || '' }}"
     strategy:
       fail-fast: false
       matrix:
         # macos-latest is apparently not the latest.
         os: [macos-13, ubuntu-latest, windows-latest]
         spm_configuration: [debug, release]
-        cmake_generator: [Ninja, Xcode]
         build_system: [cmake, spm]
 
-        exclude:
-          - os: ubuntu-latest
-            cmake_generator: Xcode
-          - os: windows-latest
+        include:
+          - cmake_generator: Ninja
+
+          - build_system: cmake
+            os: macos-13
             cmake_generator: Xcode
-          - build_system: spm
-            cmake_generator: Ninja
 
-        include:
           - HYLO_LLVM_BUILD_RELEASE: 20240303-215025
           - HYLO_LLVM_BUILD_TYPE: MinSizeRel
           - HYLO_LLVM_DOWNLOAD_URL: https://github.com/hylo-lang/llvm-build/releases/download