Bump Xcode version to 15.4

Author: dfed

.github/workflows/ci.yml

@@ -45,7 +45,7 @@ jobs:
       - name: Bundle Install
         run: bundle install
       - name: Select Xcode Version
-        run: sudo xcode-select --switch /Applications/Xcode_15.2.app/Contents/Developer
+        run: sudo xcode-select --switch /Applications/Xcode_15.4.app/Contents/Developer
       - name: Build and Test Framework
         run: Scripts/build.swift ${{ matrix.platforms }}
       - name: Prepare Coverage Reports
@@ -67,7 +67,7 @@ jobs:
       - name: Bundle Install
         run: bundle install
       - name: Select Xcode Version
-        run: sudo xcode-select --switch /Applications/Xcode_15.2.app/Contents/Developer
+        run: sudo xcode-select --switch /Applications/Xcode_15.4.app/Contents/Developer
       - name: Build and Test Framework
         run: xcrun swift test -c release -Xswiftc -enable-testing
   linux: