chore(deps): update actions/cache action to v4

Author: renovate[bot]

.github/workflows/ci.yml

@@ -131,7 +131,7 @@ jobs:
         uses: actions/setup-dotnet@v3
         with:
           dotnet-version: '6.0.x'
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
         with:
           path: ~/.nuget/packages
           # Look to see if there is a cache hit for the corresponding requirements file