chore(deps): update dependency phpstan/phpstan-phpunit to v0.12.21

This MR contains the following updates:

Package	Type	Update	Change
phpstan/phpstan-phpunit	require-dev	patch	0.12.20 -> 0.12.21

---

Release Notes

phpstan/phpstan-phpunit

v0.12.21

Compare Source

• 6aaff11 - Add support for assertArrayHasKey (#​100)

---

Configuration

📅 Schedule: "every weekend" (UTC).

🚦 Automerge: Enabled.

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

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

---

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

---

This MR has been generated by Renovate Bot.