Upgrade Kroxy support to latest 3.0.x serdes/client

[EricWittmann]

Feature or Problem Description

We have contributed support for Apicurio Registry to the kroxylicious project here:

https://github.com/kroxylicious/kroxylicious/tree/main/kroxylicious-filters/kroxylicious-record-validation

That version does not support the released upstream version of registry 3.0.

Proposed Solution

Upgrade the code in kroxy to support Registry 3.0.x.

[apicurio-bot]

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