Remove BepInEx NuGet source from build.yml

Removed BepInEx NuGet source from build workflow.

.github/workflows/build.yml

@@ -30,11 +30,6 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '6.0.x'
-        
-    - name: Add BepInEx NuGet source
-      run: |
-        # Add the BepInEx NuGet feed
-        dotnet nuget add source --name bepinex "https://nuget.bepinex.dev/v3/index.json"
     
     - name: Install PowerShell Core
       run: |