feat: update sqlx to 0.8.0

[metatoaster]

Fix: #96

[CLAassistant]

All committers have signed the CLA.

[metatoaster]

Look, the underlying CI is broken for OS X and this applies for the other pull request and I will revert this to the original maintainers to fix, as fixing OS X workflow is not something I am interested in doing nor do I have the time available to do so, given that the obvious looking error wasn't the only one.

Perhaps related, I also re-evaluated my actual needs from Casbin and this package; based on my benchmarks, generating the RBAC model+policy on the fly with data provided from the application schema related to access control fully owned by the application adds very negligible overhead (~<50 µs to create model + initiate policies associated with the incoming user/groups/resource, and 100-150 µs to enforce), and is in fact more simple and less error-prone than maintaining a parallel/synchronized Casbin policy in a separate database via packages like sqlx-adapter. Especially given that a schema controlled by the application developers addresses the need to have a controlled representation of the encoded permissions, properly integrates with the actual system, and have the encoded permissions on a per-resource basis be more cleanly presented to and managed by users of that system, while still having the property of being easily converted to a tight Casbin model+policy at the required scope for access control.