chore(deps): update dependency pytest-cov to v7 (#855)

This PR contains the following updates:

| Package | Change | Age | Confidence |
|---|---|---|---|
| [pytest-cov](https://redirect.github.com/pytest-dev/pytest-cov)
([changelog](https://pytest-cov.readthedocs.io/en/latest/changelog.html))
| `==6.3.0` -> `==7.0.0` |
[![age](https://developer.mend.io/api/mc/badges/age/pypi/pytest-cov/7.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
[![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/pytest-cov/6.3.0/7.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|

---

### Release Notes

<details>
<summary>pytest-dev/pytest-cov (pytest-cov)</summary>

###
[`v7.0.0`](https://redirect.github.com/pytest-dev/pytest-cov/blob/HEAD/CHANGELOG.rst#700-2025-09-09)

[Compare
Source](https://redirect.github.com/pytest-dev/pytest-cov/compare/v6.3.0...v7.0.0)

- Dropped support for subprocesses measurement.

It was a feature added long time ago when coverage lacked a nice way to
measure subprocesses created in tests.
It relied on a `.pth` file, there was no way to opt-out and it created
bad interations
with `coverage's new patch system
<https://coverage.readthedocs.io/en/latest/config.html#run-patch>`\_
added
in `7.10
<https://coverage.readthedocs.io/en/7.10.6/changes.html#version-7-10-0-2025-07-24>`\_.

To migrate to this release you might need to enable the suprocess patch,
example for `.coveragerc`:

  .. code-block:: ini

  \[run]
  patch = subprocess

  This release also requires at least coverage 7.10.6.
- Switched packaging to have metadata completely in `pyproject.toml` and
use `hatchling <https://pypi.org/project/hatchling/>`\_ for
  building.
Contributed by Ofek Lev in `#&#8203;551
<https://github.com/pytest-dev/pytest-cov/pull/551>`\_
with some extras in `#&#8203;716
<https://github.com/pytest-dev/pytest-cov/pull/716>`\_.
- Removed some not really necessary testing deps like `six`.

</details>

---

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requirements-test.txt

@@ -1,6 +1,6 @@
 pytest==8.4.2
 pytest-pep8==1.0.6
-pytest-cov==6.3.0
+pytest-cov==7.0.0
 pytest-aiohttp==1.1.0
 pytest-asyncio==1.1.0
 responses==0.25.8