Upload coverage after GPU tests (#2767)

Co-authored-by: Davis Bennett <[email protected]>

Author: dstansby

.github/workflows/gpu_test.yml

@@ -64,3 +64,9 @@ jobs:
     - name: Run Tests
       run: |
         hatch env run --env gputest.py${{ matrix.python-version }}-${{ matrix.numpy-version }}-${{ matrix.dependency-set }} run-coverage
+
+    - name: Upload coverage
+      uses: codecov/codecov-action@13ce06bfc6bbe3ecf90edbbf1bc32fe5978ca1d3  # v5.3.1
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}
+        verbose: true # optional (default = false)