fix: Fix list of scopes in app integrations

[jorgeajimenezl]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

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[codespearhead]

I agree with the proposed changes, as they provide a safeguard against raising an AttributeError when scope is an iterable instead of a string. However, I can't think of a case where that will ever happen.

So LGTM.

However, here's how to make it better:

As for the PR itself:

1. Squash commits 7beb8f6 and 96c8449 into a single commit.
2. Changing "openid" to 'openid' deviates from the consistent style of strings in the file and is unrelated to the PR, thus this specific change shouldn't have been included.

These changes will make it much easier to review the PR. For more information, please refer to Keycloak's PR checklist [1][2].

[1] https://github.com/keycloak/keycloak/blob/main/CONTRIBUTING.md#submitting-your-pr
[2] https://github.com/keycloak/keycloak/blob/main/CONTRIBUTING.md#contributing-to-keycloak