Bump Harmony.Extensions in /src/Bannerlord.Module.CSharp

Bumps [Harmony.Extensions](https://github.com/BUTR/Harmony.Extensions) from 2.0.0.50 to 2.0.0.51.
- [Release notes](https://github.com/BUTR/Harmony.Extensions/releases)
- [Commits](https://github.com/BUTR/Harmony.Extensions/commits)

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

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

Author: dependabot[bot]

src/Bannerlord.Module.CSharp/BLNamespace.csproj

@@ -48,7 +48,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
     <PackageReference Condition="'$(ReferenceHarmony)' == 'true'" Include="Lib.Harmony" Version="2.1.1" IncludeAssets="compile" />
-    <PackageReference Condition="'$(ReferenceHarmony)' == 'true'" Include="Harmony.Extensions" Version="2.0.0.50">
+    <PackageReference Condition="'$(ReferenceHarmony)' == 'true'" Include="Harmony.Extensions" Version="2.0.0.51">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>