Update actions/cache action to v4

Author: renovate[bot]

.github/workflows/ci-linux.yml

@@ -20,13 +20,13 @@ jobs:
         uses: actions/[email protected]
 
       - name: APT cache
-        uses: actions/cache@v3.3.1
+        uses: actions/cache@v4.1.0
         with:
           path: /var/cache/apt
           key: ${{ runner.os }}-apt
 
       - name: Restore cached SPM dependencies
-        uses: actions/cache@v3.3.1
+        uses: actions/cache@v4.1.0
         with:
           path: .build
           key: swiftpm-${{ runner.os }}-${{ inputs.swift-version }}-${{ hashFiles('Package.swift') }}

.github/workflows/ci-windows.yml

@@ -20,7 +20,7 @@ jobs:
         uses: actions/[email protected]
 
       - name: Cache vcpkg
-        uses: actions/cache@v3.3.1
+        uses: actions/cache@v4.1.0
         with:
           key: windows-x64-vcpkg
           path: C:\vcpkg\installed\x64-windows