Fix CI issues: use compatible CodeAnalysis packages and add NuGet API key validation

Author: Danielle Jenkins

src/GodotSharpAnalyzers/GodotSharpAnalyzers.csproj

@@ -19,8 +19,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.14.0" PrivateAssets="all" />
-    <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="4.14.0" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.8.0" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
     <PackageReference Include="GitVersion.MsBuild" Version="5.12.0" PrivateAssets="all" />
   </ItemGroup>