ci: add print failure info

Author: microdev1

.github/workflows/build.yml

@@ -79,6 +79,10 @@ jobs:
     - name: Test all
       run: MICROPY_CPYTHON3=python3.8 MICROPY_MICROPYTHON=../ports/unix/micropython-coverage ./run-tests.py -j1
       working-directory: tests
+    - name: Print failure info
+      run: MICROPY_CPYTHON3=python3.8 MICROPY_MICROPYTHON=../ports/unix/micropython-coverage ./run-tests.py -j1 --print-failures
+      if: failure()
+      working-directory: tests
     - name: Native Tests
       run: MICROPY_CPYTHON3=python3.8 MICROPY_MICROPYTHON=../ports/unix/micropython-coverage ./run-tests.py -j1 --emit native
       working-directory: tests