Bump SteamKit2 from 3.0.0-Alpha.2 to 3.0.0-Alpha.3

Bumps [SteamKit2](https://github.com/SteamRE/SteamKit) from 3.0.0-Alpha.2 to 3.0.0-Alpha.3.
- [Release notes](https://github.com/SteamRE/SteamKit/releases)
- [Commits](https://github.com/SteamRE/SteamKit/compare/3.0.0-Alpha.2...3.0.0-Alpha.3)

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

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

DepotDownloader/DepotDownloader.csproj

@@ -15,6 +15,6 @@
   <ItemGroup>
     <PackageReference Include="protobuf-net" Version="3.2.30" />
     <PackageReference Include="QRCoder" Version="1.6.0" />
-    <PackageReference Include="SteamKit2" Version="3.0.0-Alpha.2" />
+    <PackageReference Include="SteamKit2" Version="3.0.0-Alpha.3" />
   </ItemGroup>
 </Project>