Use Xcode 11.4 for CI builds

Author: mac-cain13

.github/workflows/checks.yml

@@ -6,6 +6,9 @@ on:
   pull_request:
     branches: '*'
 
+env:
+  DEVELOPER_DIR: /Applications/Xcode_11.4.app/Contents/Developer
+
 jobs:
   test:
     runs-on: macos-latest

.github/workflows/release.yml

@@ -5,6 +5,9 @@ on:
     types:
     - created
 
+env:
+  DEVELOPER_DIR: /Applications/Xcode_11.4.app/Contents/Developer
+
 jobs:
   release-build:
     runs-on: macos-latest
@@ -33,7 +36,7 @@ jobs:
         asset_content_type: application/zip
     - name: Publish to Cocoapods
       run: |
-        POD_VERSION=$(echo $TAG_NAME | cut -c2-)
+        export POD_VERSION=$(echo $TAG_NAME | cut -c2-)
         pod trunk push
       env:
         TAG_NAME: ${{ github.event.release.tag_name }}