chore(deps): update codecov/codecov-action action to v7 (#851)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[codecov/codecov-action](https://redirect.github.com/codecov/codecov-action)
| action | major | `v6` → `v7` |

---

### Release Notes

<details>
<summary>codecov/codecov-action (codecov/codecov-action)</summary>

###
[`v7.0.0`](https://redirect.github.com/codecov/codecov-action/compare/v7.0.0...v7.0.0)

[Compare
Source](https://redirect.github.com/codecov/codecov-action/compare/v7.0.0...v7.0.0)

###
[`v7`](https://redirect.github.com/codecov/codecov-action/compare/v6.0.1...v7.0.0)

[Compare
Source](https://redirect.github.com/codecov/codecov-action/compare/v6.0.2...v7.0.0)

</details>

---

### Configuration

📅 **Schedule**: (UTC)

- Branch creation
  - "before 7am every weekday"
- Automerge
  - At any time (no schedule defined)

🚦 **Automerge**: Disabled by config. Please merge this manually once you
are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

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.github/workflows/_checks.yaml

@@ -138,7 +138,7 @@ jobs:
             matrix.python-version == '3.14' &&
             env.CODECOV_TOKEN != ''
           }}
-        uses: codecov/codecov-action@v6
+        uses: codecov/codecov-action@v7
         with:
           token: ${{ env.CODECOV_TOKEN }}
           files: coverage-integration.xml