housekeeping: Update actions/stale action to v9

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/stale	action	major	v7 -> v9

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Release Notes

actions/stale (actions/stale)

v9

Compare Source

v8

Compare Source

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), 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.

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

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[github-actions]

This PR has been marked as stale after 7 or more days of inactivity. Please have a maintainer add the on hold label if this PR should remain open. If there is no further activity or the on hold label is not added, this PR will be closed in 3 days.

[renovate]

Renovate Ignore Notification

Because you closed this PR without merging, Renovate will ignore this update. You will not get PRs for any future 9.x releases. But if you manually upgrade to 9.x then Renovate will re-enable minor and patch updates automatically.

If you accidentally closed this PR, or if you changed your mind: rename this PR to get a fresh replacement PR.