Bump xunit from 2.9.2 to 2.9.3

---
updated-dependencies:
- dependency-name: xunit
  dependency-version: 2.9.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

backend/backend.csproj

@@ -16,7 +16,7 @@
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageReference Include="DotNetEnv" Version="3.1.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
-    <PackageReference Include="xunit" Version="2.9.2" />
+    <PackageReference Include="xunit" Version="2.9.3" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
     <PackageReference Include="Moq" Version="4.20.72" />
   </ItemGroup>