use macos-12

Author: perazz

.github/workflows/build.yaml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-11, windows-latest]
+        os: [ubuntu-latest, macos-12, windows-latest]
         gcc: [10]
 
     steps: