Update codecov token in Benchmark workflow (#5713)

### Before submitting

Please complete the following checklist when submitting a PR:

- [ ] All new features must include a unit test.
If you've fixed a bug or added code that should be tested, add a test to
the
      test directory!

- [ ] All new functions and code must be clearly commented and
documented.
If you do make documentation changes, make sure that the docs build and
      render correctly by running `make docs`.

- [ ] Ensure that the test suite passes, by running `make test`.

- [ ] Add a new entry to the `doc/releases/changelog-dev.md` file,
summarizing the
      change, and including a link back to the PR.

- [ ] The PennyLane source code conforms to
      [PEP8 standards](https://www.python.org/dev/peps/pep-0008/).
We check all of our code against [Pylint](https://www.pylint.org/).
      To lint modified files, simply `pip install pylint`, and then
      run `pylint pennylane/path/to/file.py`.

When all the above are checked, delete everything above the dashed
line and fill in the pull request template.


------------------------------------------------------------------------------------------------------------

**Context:** Adds the codecov token to the benchmark yaml file to avoid
outright failures.

**Description of the Change:** As above.

**Benefits:**

**Possible Drawbacks:**

**Related GitHub Issues:**

.github/workflows/benchmarks.yml

@@ -25,6 +25,8 @@ jobs:
  if: github.event_name == 'schedule' || (github.event_name == 'pull_request' && contains(github.event.pull_request.labels.*.name, 'ci:run-benchmarks'))
 
  uses: ./.github/workflows/interface-unit-tests.yml
+ secrets:
+ codecov_token: ${{ secrets.CODECOV_TOKEN }}
  with:
  # If running by workflow call, will check by provided ref_branch, if not will default to 'add-pytest-benchmarks'.
  branch: ${{ inputs.ref_branch || 'add-pytest-benchmarks' }}
@@ -47,6 +49,8 @@ jobs:
  if: github.event_name == 'schedule' || (github.event_name == 'pull_request' && contains(github.event.pull_request.labels.*.name, 'ci:run-benchmarks'))
 
  uses: ./.github/workflows/interface-unit-tests.yml
+ secrets:
+ codecov_token: ${{ secrets.CODECOV_TOKEN }}
  needs: reference-benchmarks
  with:
  # If running by workflow call, will check by provided branch, if not will default to github.ref.