do not set developer dir manually

Signed-off-by: David Nadoba <[email protected]>

Author: dnadoba

.github/workflows/swift.yml

@@ -50,8 +50,6 @@ jobs:
       with:
         xcode-version: ${{ matrix.xcode }}
     - name: Build & Run Performance Tests on macOS
-      env:
-        DEVELOPER_DIR: ${{ matrix.xcode }}
       run: >
         swift test
         --configuration=release