Bump ppy.osu.Game from 2021.602.0 to 2021.608.0

Bumps [ppy.osu.Game](https://github.com/ppy/osu) from 2021.602.0 to 2021.608.0.
- [Release notes](https://github.com/ppy/osu/releases)
- [Commits](ppy/osu@2021.602.0...2021.608.0)

---
updated-dependencies:
- dependency-name: ppy.osu.Game
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

osu.Game.Rulesets.Rush/osu.Game.Rulesets.Rush.csproj

@@ -33,6 +33,6 @@
     </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="ppy.osu.Game" Version="2021.602.0" />
+    <PackageReference Include="ppy.osu.Game" Version="2021.608.0" />
   </ItemGroup>
 </Project>