Use the TUNIT_DISABLE_GITHUB_REPORTER environment variable

Thanks to thomhurst/TUnit#2716

Author: 0xced

.github/workflows/continuous-integration.yml

@@ -54,7 +54,7 @@ jobs:
         run: dotnet run --project tools/mmd/mmd.csproj -- README.md ${{ github.sha }} README.md
       - name: 🧪 Run tests
         env:
-          DISABLE_GITHUB_REPORTER: true
+          TUNIT_DISABLE_GITHUB_REPORTER: true
         # The .nupkg file is created as part of integration tests
         run: dotnet test --no-build
       - name: 📤 Upload test results