ci: use cache v4

Author: Tarmil

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
           dotnet-version: '6.0.100'
 
       - name: NuGet cache
-        uses: actions/cache@v1
+        uses: actions/cache@v4
         with:
           path: ~/.nuget/packages
           key: ${{ runner.os }}-nuget-${{ hashFiles('.config/dotnet-tools.json') }}-${{ hashFiles('*.lock') }}