Update test project path in unit-tests.yml for cross-platform use

- Changed backslash to forward slash in test project path
- Ensures compatibility with both Windows and Unix-like systems

Author: jsakamoto

.github/workflows/unit-tests.yml

@@ -25,4 +25,4 @@ jobs:
       - name: Perform the source generator tests
         run: dotnet test --project ./Toolbelt.Blazor.I18nText.SourceGenerator.Test --output detailed
       - name: Perform the compiler task tests
-        run: dotnet test --project .\Toolbelt.Blazor.I18nText.CompileTask.Test --output detailed
+        run: dotnet test --project ./Toolbelt.Blazor.I18nText.CompileTask.Test --output detailed