Fix scaler leak during cache refresh

[gjacquet]

Fixes scaler not being properly closed in performGetScalerCache:

• Fix logic to close scaler when out of date
• Fix race confition

Checklist

• [x] When introducing a new scaler, I agree with the scaling governance policy
• [x] I have verified that my change is according to the deprecations & breaking changes policy
• [ ] Tests have been added
• [x] Changelog has been updated and is aligned with our changelog requirements
• [ ] A PR is opened to update our Helm chart (repo) (if applicable, ie. when deployment manifests are modified)
• [ ] A PR is opened to update the documentation on (repo) (if applicable)
• [x] Commits are signed with Developer Certificate of Origin (DCO - learn more)

Fixes #5806

[zroubalik]

/run-e2e Update: You can check the progress here

[zroubalik]

@gjacquet can you confirm that this fix helped with the issues in your env?

[gjacquet]

@zroubalik Thanks for reviewing! I have been running this patch in two of our non-production environments and it solved this issue.

[zroubalik]

Thanks, this is really great fix

[JorTurFer]

Awesome catch! Thanks for the fix :heart: