Fix coverage workflow (#4146)

* Remove quotes from the if-statement

* Adjust logic

* Fix job naming

* Change order

.github/workflows/test_on_push.yml

@@ -105,24 +105,23 @@ jobs:
         if: matrix.os != 'windows-latest'
         run: python -m nox -s pybamm-requires
 
-      - name: Run unit/coverage tests for ${{ matrix.os }} with Python ${{ matrix.python-version }}
-        shell: bash
-        run: |
-          if [ ${{ matrix.python-version }} == "3.12" && ${{ matrix.os }} == "ubuntu-latest" ]; then
-            python -m nox -s coverage
-          else
-            python -m nox -s unit
-          fi
+      - name: Run unit tests for ${{ matrix.os }} with Python ${{ matrix.python-version }}
+        if: matrix.os != 'ubuntu-latest' || matrix.python-version != '3.12'
+        run: python -m nox -s unit
 
-      - name: Run integration tests for ${{ matrix.os }} with Python ${{ matrix.python-version }}
-        run: python -m nox -s integration
+      - name: Run coverage tests for ${{ matrix.os }} with Python ${{ matrix.python-version }}
+        if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.12'
+        run: python -m nox -s coverage
 
       - name: Upload coverage report
         if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.12'
         uses: codecov/codecov-action@v4.4.1
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
 
+      - name: Run integration tests for ${{ matrix.os }} with Python ${{ matrix.python-version }}
+        run: python -m nox -s integration
+
   # Skips IDAKLU module compilation for speedups, which is already tested in other jobs.
   run_doctests:
     needs: style