gha: update to use macos-12 runners

It's the minimum version supported by Docker Desktop

Signed-off-by: Sebastiaan van Stijn <[email protected]>

.github/workflows/test.yml

@@ -45,7 +45,7 @@ jobs:
       fail-fast: false
       matrix:
         os:
-          - macos-11
+          - macos-12
 #          - windows-2022 # FIXME: some tests are failing on the Windows runner, as well as on Appveyor since June 24, 2018: https://ci.appveyor.com/project/docker/cli/history
     steps:
       -