fix: Cors config values are ignored

[vancanhuit]

Related issue(s)

closes #788

Checklist

• I have read the contributing guidelines.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• I am following the
  contributing code guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security. vulnerability, I
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  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

Further Comments

[zepatrik]

Thanks, the changes look good. The CI failure seems unrelated. I will fix it separately and then merge this once ✔️

[zepatrik]

🎉 Thanks again, I added a small test and fixed the config provider accordingly, as I was on it already.