feat: use dart-dio now that it supports polymorphism

[AllenKaplan]

Description

After months of work dart-dio has been updated with furthered support of OAS3 https://github.com/OpenAPITools/openapi-generator/pull/12295

It would be in user's interest to use the more encompassing dart generator leveraging dio (replacement of dart's http pkg) with OAS3 polymorphism support

Related Issue or Design Document

Previous PR to switch off dart-dio due to issues with not generating flutter 3 compatible code https://github.com/ory/sdk/pull/202

Checklist

• [X] I have read the contributing guidelines and signed the CLA.
• [ ] I have referenced an issue containing the design document if my change introduces a new feature.
• [X] I have read the security policy.
• [X] I confirm that this pull request does not address a security vulnerability. If this pull request addresses a security vulnerability, I confirm that I got green light (please contact security@ory.sh) from the maintainers to push the changes.
• [ ] I have added tests that prove my fix is effective or that my feature works.
• [ ] I have added necessary documentation within the code base (if appropriate).

Further comments

Full disclosure I have not tested generating Ory SDK with dart over dart-dio 🙊

[aeneasr]

Awesome, thank you! 🎉 Your contribution makes Ory better :)