Fix GitHub Actions workflows for .slnx compatibility

- Specify SWEN3.Paperless.RabbitMq.sln explicitly in restore steps
- Prevents MSB1011 error when both .sln and .slnx files exist
- Add xunit.v3.runner.json to test project
- Fix accidental file path in GenAIExtensionsTests.cs

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: ANcpLua

.github/workflows/nuget-publish.yml

@@ -87,7 +87,7 @@ jobs:
           args: convert icon.png -trim -resize 512x512 -gravity center -background transparent -extent 512x512 icon.png
 
       - name: Restore dependencies
-        run: dotnet restore
+        run: dotnet restore SWEN3.Paperless.RabbitMq.sln
 
       - name: Build solution
         run: dotnet build --configuration Release --no-restore

.github/workflows/tests.yml

@@ -21,7 +21,7 @@ jobs:
             10.0.x
 
       - name: Restore dependencies
-        run: dotnet restore
+        run: dotnet restore SWEN3.Paperless.RabbitMq.sln
 
       - name: Build
         run: dotnet build --no-restore --configuration Release

SWEN3.Paperless.RabbitMq.Tests/SWEN3.Paperless.RabbitMq.Tests.csproj

@@ -43,7 +43,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Compile Include="Helpers\SseTestHelpers.cs" />
+    <Content Include="xunit.v3.runner.json" CopyToOutputDirectory="PreserveNewest"/>
   </ItemGroup>
 
 </Project>