CI: test older macos builds

Author: PMeira

.github/workflows/builds.yml

@@ -71,10 +71,10 @@ jobs:
     strategy:
       matrix:
         include:
-          - os: macos-15-intel
+          - os: macos-14-large
             arch: x64
             extra_cmake_flags: '-DCMAKE_POLICY_VERSION_MINIMUM=3.5'
-          - os: macos-latest
+          - os: macos-14
             arch: arm64
             extra_cmake_flags: '-DCMAKE_POLICY_VERSION_MINIMUM=3.5'
 
@@ -84,6 +84,8 @@ jobs:
       KLUSOLVE_ARCH: ${{ matrix.arch }}
       EIGEN_VERSION : "5.0.0"
       KLUSOLVE_EXTRA_CMAKE_FLAGS: ${{ matrix.extra_cmake_flags }}
+      MACOSX_DEPLOYMENT_TARGET: '11.0'
+      
     steps:
       - uses: "actions/checkout@v4"
         with: