support macOS 10.14 Mojave for x86_64 deployment

Author: wenfeng song

Diff for: .github/workflows/main.yml

@@ -52,7 +52,7 @@ jobs:
     name: 'MacOS-x86_64'
     runs-on: [macos-12]
     env:
-      MACOSX_DEPLOYMENT_TARGET_X86_64: '10.15'
+      MACOSX_DEPLOYMENT_TARGET_X86_64: '10.14'
       SPARKLE_VERSION: '1.26.0'
       SPARKLE_HASH: '8312cbf7528297a49f1b97692c33cb8d33254c396dc51be394e9484e4b6833a0'
       BLOCKED_FORMULAS: 'speexdsp curl php composer'