Update ci-build.yml

Author: hhvrc

.github/workflows/ci-build.yml

@@ -55,7 +55,7 @@ jobs:
           dotnet-version: ${{ env.DOTNET_VERSION }}
 
       - name: Cache NuGet packages
-        uses: actions/cache@v6
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9  # v6.1.0
         with:
           path: ~/.nuget/packages
           key: ${{ matrix.os }}-tests-nuget-${{ hashFiles('**/*.csproj', 'Directory.Packages.props') }}