Add missing `openid` scope when requesting JWT token in Zitadel

[glaeqen]

Describe your changes

According to the Zitadel documentation, openid scope is required when requesting JWT tokens.

Apparently Zitadel was accepting requests without it until very recently. Now lack thereof causes 400 Bad Requests which makes it impossible to authenticate to the Netbird dashboard.

https://zitadel.com/docs/guides/integrate/service-users/client-credentials#2-authenticating-a-service-user-and-request-a-token

Issue ticket number and link

None

Checklist

• [x] Is it a bug fix
• [ ] Is a typo/documentation fix
• [ ] Is a feature enhancement
• [ ] It is a refactor
• [ ] Created tests that fail without the change (if possible)
• [ ] Extended the README / documentation, if necessary

[CLAassistant]

All committers have signed the CLA.

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

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