bot (deps): bump reactiveui from 18.4.20 to 18.4.25 in /Cosmic.NET (#76)

Bumps [reactiveui](https://github.com/reactiveui/reactiveui) from 18.4.20 to 18.4.25.
- [Release notes](https://github.com/reactiveui/reactiveui/releases)
- [Commits](reactiveui/ReactiveUI@18.4.20...18.4.25)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

cosmo/Cosmo.csproj

@@ -7,6 +7,6 @@
     <Copyright>Copyright © Joshua Kempner 2008-2022</Copyright>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="reactiveui" Version="18.4.20" />
+    <PackageReference Include="reactiveui" Version="18.4.25" />
   </ItemGroup>
 </Project>