build: bump Krafs.Rimworld.Ref from 1.4.3704 to 1.4.3901

Bumps [Krafs.Rimworld.Ref](https://github.com/krafs/RimRef) from 1.4.3704 to 1.4.3901.
- [Commits](https://github.com/krafs/RimRef/commits)

---
updated-dependencies:
- dependency-name: Krafs.Rimworld.Ref
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

LevelUp.csproj

@@ -16,7 +16,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Krafs.Rimworld.Ref" Version="1.4.3704" />
+    <PackageReference Include="Krafs.Rimworld.Ref" Version="1.4.3901" />
     <PackageReference Include="Lib.Harmony" Version="2.2.2" ExcludeAssets="runtime" />
   </ItemGroup>