Bump LiteDB from 5.0.16 to 5.0.21

Bumps [LiteDB](https://github.com/mbdavid/LiteDB) from 5.0.16 to 5.0.21.
- [Release notes](https://github.com/mbdavid/LiteDB/releases)
- [Commits](litedb-org/LiteDB@v5.0.16...v5.0.21)

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

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

StabilityMatrix/StabilityMatrix.csproj

@@ -19,7 +19,7 @@
     <PackageReference Include="Blake3" Version="0.5.1" />
     <PackageReference Include="CommunityToolkit.Mvvm" Version="8.2.1" />
     <PackageReference Include="FuzzySharp" Version="2.0.2" />
-    <PackageReference Include="LiteDB" Version="5.0.16" />
+    <PackageReference Include="LiteDB" Version="5.0.21" />
     <PackageReference Include="LiteDB.Async" Version="0.1.6" />
     <PackageReference Include="MdXaml" Version="1.20.1" />
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="7.0.0" />