Bump EntityFramework from 6.2.0 to 6.4.4

Bumps [EntityFramework](https://github.com/dotnet/ef6) from 6.2.0 to 6.4.4.
- [Release notes](https://github.com/dotnet/ef6/releases)
- [Commits](dotnet/ef6@6.2.0...v6.4.4)

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

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

src/Moq.Tests/Moq.Tests.csproj

@@ -47,7 +47,7 @@
   </ItemGroup>
 
   <ItemGroup Condition=" $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', 'FEATURE_EF'))">
-		<PackageReference Include="EntityFramework" Version="6.2.0" />
+		<PackageReference Include="EntityFramework" Version="6.4.4" />
 	</ItemGroup>
 
 	<ItemGroup Condition=" $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', 'FEATURE_SYSTEM_WEB'))">