Bug: Check for "none" when checking pod identity provider

[joelsmith]

The prometheus scaler should expect a value of "none" to determine
that no pod identity provider is set.

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Fixes #4695

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[joelsmith]

@zroubalik PTAL. Thanks!

[JorTurFer]

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

[JorTurFer]

Thanks for the fix @joelsmith <3
Checking the change, it should happen on any instance of KEDA, but I couldn't reproduce it using latest core (and I tried with exactly the same values as the user). Is there any change in OpenShift code at some point?

[joelsmith]

I could only reproduce that error if I included this stanza:

spec:
  podIdentity: 
    provider: none

which the reporter mentioned as something they once tried. I did run into an issue where a change to the trigger auth object didn't cause the scaled object to re-reconcile, so adding or removing that stanza didn't have any effect unless the scaled object was created after the trigger auth. So my best guess is that the reporter's logs came from a time where the initial trigger auth had the stanza when the scaled object was created. In other words, while I think this is a good fix, I am guessing that there is more to the problem the reporter was having and this is more of a side issue, not the actual issue causing it to fail. Hopefully I am wrong and the new version with the fix starts working for them.