Bump MongoDB.Driver from 2.14.1 to 2.15.0

Bumps [MongoDB.Driver](https://github.com/mongodb/mongo-csharp-driver) from 2.14.1 to 2.15.0.
- [Release notes](https://github.com/mongodb/mongo-csharp-driver/releases)
- [Commits](mongodb/mongo-csharp-driver@v2.14.1...v2.15.0)

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

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

src/KickStart.MongoDB/KickStart.MongoDB.csproj

@@ -11,7 +11,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="MongoDB.Driver" Version="2.14.1" />
+    <PackageReference Include="MongoDB.Driver" Version="2.15.0" />
   </ItemGroup>
 
 </Project>

test/KickStart.MongoDB.Tests/KickStart.MongoDB.Tests.csproj

@@ -27,7 +27,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="MongoDB.Driver" Version="2.14.1" />
+    <PackageReference Include="MongoDB.Driver" Version="2.15.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="FluentAssertions" Version="6.3.0" />
   </ItemGroup>