change min mac build from 10.14 to 10.15

Author: electronstudio

.github/workflows/build.yml

@@ -18,8 +18,6 @@ jobs:
     strategy:
       matrix:
         python-version: [ '3.7', '3.8', '3.9', '3.10', '3.11.0-alpha - 3.11.0',  'pypy-3.7', 'pypy-3.8', 'pypy-3.9' ]
-    env:
-      MACOSX_DEPLOYMENT_TARGET: 10.14
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v2
@@ -62,7 +60,7 @@ jobs:
     runs-on: macos-12
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11.0-alpha - 3.11.0' ]
+        python-version: ['3.10', '3.11.0-alpha - 3.11.0' ]
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v2