Limit macos build to 13.1

Author: dankmolot

.github/workflows/build.yml

@@ -34,7 +34,7 @@ jobs:
           - os: ubuntu-20.04
             arch: x86
             CMAKE_ARCH_FLAG: -DCMAKE_C_FLAGS="-m32" -DCMAKE_CXX_FLAGS="-m32"
-          - os: macos-latest
+          - os: macos-13
             arch: x64
 
     runs-on: ${{ matrix.os }}