Attempt to fix osx-x64 builds by pinning xcode version

Author: dihm

.github/workflows/release.yml

@@ -123,6 +123,12 @@ jobs:
           architecture: ${{ matrix.arch }}
           miniconda-version: "latest"
 
+      - name: Configure xcode
+        if: matrix.os == 'macos-13'
+        uses: maxim-lobanov/setup-xcode@v1
+        with:
+          xcode-version: 14.3
+
       - name: Conda package (Unix)
         if: (matrix.conda && runner.os != 'Windows')
         shell: bash -l {0}