[E402] Allow cell magics before an import

[dhruvmanila]

Summary

This PR fixes the bug to allow Ipython escape commands to be present before an import statement and avoid raising E402.

fixes: #10357

Test Plan

Add test case and make sure they don't raise the E402 violation.

On main, we get the following:

crates/ruff_linter/resources/test/fixtures/pycodestyle/E402.ipynb:cell 8:2:1: E402 Module level import not at top of cell
  |
1 | %%time
2 | import pathlib
  | ^^^^^^^^^^^^^^ E402
  |

crates/ruff_linter/resources/test/fixtures/pycodestyle/E402.ipynb:cell 10:3:1: E402 Module level import not at top of cell
  |
1 | %%time
2 | %%time
3 | import pathlib
  | ^^^^^^^^^^^^^^ E402

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.