Bump MongoDB.Driver from 2.19.1 to 2.20.0

Bumps [MongoDB.Driver](https://github.com/mongodb/mongo-csharp-driver) from 2.19.1 to 2.20.0.
- [Release notes](https://github.com/mongodb/mongo-csharp-driver/releases)
- [Commits](mongodb/mongo-csharp-driver@v2.19.1...v2.20.0)

---
updated-dependencies:
- dependency-name: MongoDB.Driver
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

src/Akka.Persistence.MongoDb/Akka.Persistence.MongoDb.csproj

@@ -11,6 +11,6 @@
   <ItemGroup>
     <PackageReference Include="Akka.Persistence.Query" Version="$(AkkaVersion)" />
     <PackageReference Include="akka.streams" Version="$(AkkaVersion)" />
-    <PackageReference Include="MongoDB.Driver" Version="2.19.1" />
+    <PackageReference Include="MongoDB.Driver" Version="2.20.0" />
   </ItemGroup>
 </Project>