Update dependency coverage to v7.6.8

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
coverage	7.6.7 -> 7.6.8

---

Release Notes

nedbat/coveragepy (coverage)

v7.6.8

Compare Source

• Fix: the LCOV report code assumed that a branch line that took no branches
  meant that the entire line was unexecuted. This isn't true in a few cases:
  the line might always raise an exception, or might have been optimized away.
  Fixes issue 1896_.

• Fix: similarly, the HTML report will now explain that a line that jumps to
  none of its expected destinations must have always raised an exception.
  Previously, it would say something nonsensical like, "line 4 didn't jump to
  line 5 because line 4 was never true, and it didn't jump to line 7 because
  line 4 was always true." This was also shown in issue 1896_.

.. _issue 1896:https://github.com/nedbat/coveragepy/issues/18966

.. _changes_7-6-7:

---

Configuration

📅 Schedule: Branch creation - "before 4am" (UTC), Automerge - "before 4am" (UTC).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

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

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.