revert change to workflow build ext charts

[aalves08]

Summary

Fixes #15675

Occurred changes and/or fixed issues

• revert change to workflow build ext charts so that extensions users can build their extensions

Technical notes summary

Areas or cases that should be tested

Areas which could experience regressions

Screenshot/Video

Checklist

• The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
• The PR has a Milestone
• The PR template has been filled out
• The PR has been self reviewed
• The PR has a reviewer assigned
• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
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• The PR has considered, and if applicable tested with, the three Global Roles Admin, Standard User and User Base

[aalves08]

Closing in favor of #15675

[nwmac]

LGTM