ci: Updates project configuration and dependencies

Configures Dependabot for monthly Swift package dependency updates.

Updates the Swift workflow to use macOS 15 and Xcode 16.4.

Updates swift-syntax dependency to the latest version.

Removes renovate configuration, as dependabot is now configured.

Author: EnesKaraosman

.github/dependabot.yml

@@ -0,0 +1,16 @@
+# Dependabot configuration: scans Swift Package Manager dependencies monthly
+version: 2
+updates:
+  - package-ecosystem: "swift"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+      day: "first"
+      time: "04:00"
+      timezone: "UTC"
+    open-pull-requests-limit: 5
+    rebase-strategy: "auto"
+    # Label PRs created by Dependabot for easier filtering
+    labels:
+      - "dependencies"
+      - "dependabot"

.github/workflows/swift.yml

@@ -12,17 +12,17 @@ on:
 jobs:
   build:
 
-    runs-on: macos-14
+    runs-on: macos-15
 
     steps:
     - uses: actions/checkout@v5
 
     - name: List Xcode installations
       run: sudo ls -1 /Applications | grep "Xcode"
 
-    - name: Select Xcode 15.2
-      run: sudo xcode-select -s /Applications/Xcode_15.2.app/Contents/Developer
-    
+    - name: Select Xcode 16.4
+      run: sudo xcode-select -s /Applications/Xcode_16.4.app/Contents/Developer
+
     - name: Build
       run: swift build -v