Update MacOS runners to 12 in workflow

Author: haubie

.github/workflows/release.yml

@@ -23,8 +23,8 @@ jobs:
       matrix:
         nif: ["2.15"]
         job:
-          - { target: aarch64-apple-darwin, os: macos-11 }
-          - { target: x86_64-apple-darwin, os: macos-11 }
+          - { target: aarch64-apple-darwin, os: macos-12 }
+          - { target: x86_64-apple-darwin, os: macos-12 }
           - {
               target: x86_64-unknown-linux-gnu,
               os: ubuntu-20.04,