Add macos-12 everywhere

Author: finestructure

.github/workflows/ci.yml

@@ -40,7 +40,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-11, ubuntu-20.04]
+        # https://github.com/actions/virtual-environments
+        os: [macos-12, macos-11, ubuntu-20.04]
 
     runs-on: ${{ matrix.os }}
     env:
@@ -55,7 +56,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-11, ubuntu-20.04]
+        # https://github.com/actions/virtual-environments
+        os: [macos-12, macos-11, ubuntu-20.04]
 
     runs-on: ${{ matrix.os }}
     env: