Remove macos-12 from CI as it is deprecated

Signed-off-by: Paul Guyot <pguyot@kallisys.net>

Author: pguyot

.github/workflows/build-and-test-macos.yaml

@@ -37,7 +37,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: ["macos-12", "macos-13", "macos-14", "macos-15"]
+        os: ["macos-13", "macos-14", "macos-15"]
         otp: ["24", "25", "26", "27"]
 
     steps: