Add Akeyless Trigger Authentication

[kgal-akl]

Checklist

• Tests have been added
• Changelog has been updated and is aligned with our changelog requirements
• A PR is opened to update the documentation: Add Akeyless Docs keda-docs#1657
• Commits are signed with Developer Certificate of Origin (DCO - learn more)

Fixes #7307.

[github-actions]

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[snyk-io]

⚠️ Snyk checks are incomplete.

Status	Scanner	Critical	High	Medium	Low	Total (0)
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[zroubalik]

Could uou please also add e2e tests? https://github.com/kedacore/keda/tree/main/tests/secret-providers

[kgal-akl]

@zroubalik added e2e tests in e2e176b

[JorTurFer]

Thanks for the contribution!

Please review all the logs, almost all are debug logs but they're printed as info.

I've kept some comments inline too (tomorrow I'll try to continue reviewing the code)

[kgal-akl]

Please review all the logs, almost all are debug logs but they're printed as info.

Addressed in 96dfca7.