Bump Github runners to Xcode version 16

Author: wallisch

.github/workflows/unit_tests.yml

@@ -26,7 +26,7 @@ jobs:
     - name: Setup Xcode
       uses: maxim-lobanov/setup-xcode@v1
       with:
-        xcode-version: 15
+        xcode-version: 16
     - name: Checkout
       uses: actions/checkout@v3
       with:
@@ -48,7 +48,7 @@ jobs:
     - name: Setup Xcode
       uses: maxim-lobanov/setup-xcode@v1
       with:
-        xcode-version: 15
+        xcode-version: 16
     - name: Checkout
       uses: actions/checkout@v3
       with:
@@ -66,7 +66,7 @@ jobs:
     - name: Setup Xcode
       uses: maxim-lobanov/setup-xcode@v1
       with:
-        xcode-version: 15
+        xcode-version: 16
     - name: Checkout
       uses: actions/checkout@v3
       with:

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:6.0
+// swift-tools-version: 6.0
 import PackageDescription
 
 let package = Package(