Bump SIL.Core.Desktop and SIL.Core in /Backend.Tests

Bumps [SIL.Core.Desktop](https://github.com/sillsdev/libpalaso) and [SIL.Core](https://github.com/sillsdev/libpalaso). These dependencies needed to be updated together.

Updates `SIL.Core.Desktop` from 14.0.0 to 14.1.1
- [Release notes](https://github.com/sillsdev/libpalaso/releases)
- [Changelog](https://github.com/sillsdev/libpalaso/blob/master/CHANGELOG.md)
- [Commits](sillsdev/libpalaso@v14.0.0...v14.1.1)

Updates `SIL.Core` from 14.0.0 to 14.1.1
- [Release notes](https://github.com/sillsdev/libpalaso/releases)
- [Changelog](https://github.com/sillsdev/libpalaso/blob/master/CHANGELOG.md)
- [Commits](sillsdev/libpalaso@v14.0.0...v14.1.1)

---
updated-dependencies:
- dependency-name: SIL.Core.Desktop
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: SIL.Core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Backend/BackendFramework.csproj

@@ -24,8 +24,8 @@
     <!-- SIL Maintained Dependencies. -->
     <PackageReference Include="icu.net" Version="2.9.0" />
     <PackageReference Include="Icu4c.Win.Full.Lib" Version="62.2.1-beta" />
-    <PackageReference Include="SIL.Core" Version="14.0.0" />
-    <PackageReference Include="SIL.Core.Desktop" Version="14.0.0">
+    <PackageReference Include="SIL.Core" Version="14.1.1" />
+    <PackageReference Include="SIL.Core.Desktop" Version="14.1.1">
       <NoWarn>NU1701</NoWarn>
     </PackageReference>
     <PackageReference Include="SIL.DictionaryServices" Version="13.0.1">