Update workflow to use ubuntu-latest for test jobs

Replaced matrix-based OS selection with a fixed `ubuntu-latest` runner. This simplifies the workflow configuration and ensures consistency across test runs. Further adjustments can be made if OS diversity becomes necessary.

Author: jeffersongoncalves

.github/workflows/run-tests.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   test:
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: true
       matrix: