chore: Drop macos-12 build (#86)

Author: keelerm84

.github/workflows/ci.yml

@@ -23,9 +23,6 @@ jobs:
           - xcode-version: 14.3.1
             ios-sim: 'platform=iOS Simulator,name=iPhone 16,OS=16.4'
             os: macos-13
-          - xcode-version: 13.4.1
-            ios-sim: 'platform=iOS Simulator,name=iPhone 11,OS=15.5'
-            os: macos-12
 
     steps:
       - uses: actions/checkout@v4