[Okta] Make URL config option a required parameter

[legoguy1000]

What does this PR do?

Mark URL as required parameter

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.

Author's Checklist

• [ ]

How to test this PR locally

Related issues

• Closes [Okta] url should a required field #4413

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• Start Time: 2022-10-09T14:21:01.508+0000

• Duration: 14 min 43 sec

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Passed	12
Skipped	0
Total	12

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[andrewkroh]

LGTM. Thank you!

[andrewkroh]

/test

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Data stream	Previous EPS	New EPS	Diff (%)	Result
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Name	Metrics % (covered/total)	Diff
Packages	100.0% (1/1)	💚
Files	100.0% (1/1)	💚 2.963
Classes	100.0% (1/1)	💚 2.963
Methods	100.0% (17/17)	💚 10.327
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