Fix some issues with extensions creator's package in release 2.8

[aalves08]

Summary

Fixes #12635

Occurred changes and/or fixed issues

• fix build-extension-charts workflow
• bump creators version

Technical notes summary

https://www.npmjs.com/package/@rancher/create-extension?activeTab=versions

Areas or cases that should be tested

Areas which could experience regressions

Screenshot/Video

Checklist

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