Set Xcode to 15.3

Author: backslash-f

.github/workflows/swift.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
       - uses: maxim-lobanov/setup-xcode@v1
         with:
-          xcode-version: '15.1'
+          xcode-version: '15.3'
       - uses: actions/checkout@v4
       - name: Run Tests
         run: swift test -v