Bump System.Linq.Dynamic.Core from 1.6.7 to 1.6.9

---
updated-dependencies:
- dependency-name: System.Linq.Dynamic.Core
  dependency-version: 1.6.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

src/Foundatio.CommandQuery.MongoDB/Foundatio.CommandQuery.MongoDB.csproj

@@ -13,7 +13,7 @@
 
   <ItemGroup>
     <PackageReference Include="MongoDB.Driver" Version="3.5.0" />
-    <PackageReference Include="System.Linq.Dynamic.Core" Version="1.6.7" />
+    <PackageReference Include="System.Linq.Dynamic.Core" Version="1.6.9" />
   </ItemGroup>
 
   <ItemGroup>