Allow CA dirs to be specified beyond /custom/ca/

[joelsmith]

Add --ca-dir flag to KEDA operator to specify directories with CA certificates for scalers to authenticate TLS connections (defaults to /custom/ca)

Checklist

• I have verified that my change is according to the deprecations & breaking changes policy
• Tests have been added
• 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)
• Commits are signed with Developer Certificate of Origin (DCO - learn more)

Fixes #5860

See kedacore/charts#650
See kedacore/keda-docs#1402

[zroubalik]

@joelsmith could you please create an issue to track this feature and link it in the changelog & docs/helm PRs then? Thanks

[joelsmith]

Hi @zroubalik, I have created the issue and the docs & chart PRs. I think they are ready for a review.
Thanks!

[zroubalik]

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

[joelsmith]

BTW, because of the added loop and resulting indent increase, the patch is easier to read with ?w=1 added to the URL, like this:
https://github.com/kedacore/keda/pull/5859/files?w=1
I'm not sure why the e2e failed... the error shows that the KEDA operator did not become ready fast enough, but looking at the operator's log, it did become ready. So maybe it was just too slow.

[zroubalik]

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

[joelsmith]

@zroubalik Thanks for re-running the test -- it passed this time. Thanks!

[zroubalik]

LGTM

I would like @JorTurFer to check this one as well

[JorTurFer]

LGTM! Only small comment inline

[JorTurFer]

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

[JorTurFer]

LGTM! Nice improvement ❤️