Update actions/cache action to v4

Author: renovate[bot]

.github/workflows/main.yml

@@ -37,7 +37,7 @@ jobs:
         uses: actions/checkout@v3
 
       - name: NuGet cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ env.NUGET_PACKAGES }}
           key: ${{ runner.os }}.nuget.${{ hashFiles('**/*.csproj', '**/*.fsproj') }}

.github/workflows/release.yml

@@ -32,7 +32,7 @@ jobs:
         run: echo "version=$(./Scripts/Get-Version.ps1 -RefName $env:GITHUB_REF)" >> $env:GITHUB_OUTPUT
 
       - name: NuGet cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ env.NUGET_PACKAGES }}
           key: release.nuget.${{ hashFiles('**/*.csproj', '**/*.fsproj') }}