chore: Remove deprecated AAD-Pod-Identity and AWS-KIAM auths

[JorTurFer]

Both auth were deprecated and we have to remove it for v2.15.
I know there are still some references to ActiveDirectoyEndpoint which aren't directly required either because we won't support aad-pod-identity anymore. They will be removed as part of this other PR that supports new SDKs and the merge conflicts will already be terrible without removing more fields than the strictly required on this PR

Checklist

• 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 #5035
Fixes #5085

[JorTurFer]

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

[JorTurFer]

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

[vladimirglazkov]

Hey @JorTurFer !
There is an announcement that AAD Pod Identity support will be removed in 2.15.
https://keda.sh/docs/2.14/authentication-providers/azure-ad-pod-identity/
So why did you remove it in 2.14?

[JorTurFer]

So why did you remove it in 2.14?

What do you mean? v2.14 still has support for it: https://github.com/kedacore/keda/blob/release/v2.14/pkg/scalers/azure/azure_aad_podidentity.go

We have just removed it from the main branch, but it means that next version won't have it. Are you using ´main´ tag?

[vladimirglazkov]

So why did you remove it in 2.14?

What do you mean? v2.14 still has support for it: https://github.com/kedacore/keda/blob/release/v2.14/pkg/scalers/azure/azure_aad_podidentity.go

We have just removed it from the main branch, but it means that next version won't have it. Are you using ´main´ tag?

I've spent some time on researching and figure it out.
kedacore/charts#625

We have Keda installed in another namespace than we're watching into, so the resolution was to add that namespace to watchNamespace parameter. Sorry for bothering you!

We're also migration to Workload Identity and the error triggered me to think that it might be related to the change.