Action is ignoring non-stale tag on issues.

[NotLazy]

Description: I've configured the stale action to not mark issues with the !stale label as stale, using exempt-issue-labels: \!stale which was working for some time when I added it 7 months ago, but for the last 3-4 months it's been ignoring the label

Action version: v5

Platform:

• Ubuntu
• macOS
• Windows
  The runner is configured to use ubuntu-latest

Runner type:

• Hosted
• Self-hosted
  Github runs the action automatically.

Repro steps: https://github.com/hainguyents13/mechvibes/blob/master/.github/workflows/stale.yml

Expected behavior: I expect the issues to not be marked as stale, as was previously working 6-7 months ago.

Actual behavior: Issues which should not be marked stale are being marked stale.