Bump SteamKit2 from 3.3.1 to 3.4.0

---
updated-dependencies:
- dependency-name: SteamKit2
  dependency-version: 3.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

DepotDownloader/DepotDownloader.csproj

@@ -27,6 +27,6 @@
     </PackageReference>
     <PackageReference Include="protobuf-net" Version="3.2.56" />
     <PackageReference Include="QRCoder" Version="1.7.0" />
-    <PackageReference Include="SteamKit2" Version="3.3.1" />
+    <PackageReference Include="SteamKit2" Version="3.4.0" />
   </ItemGroup>
 </Project>