Fix release issues

[sdadn]

Summary

This PR fixes some issues with the recent release caused by missing files. e.g.

This PR fixes it by removing the unnecessary postinstall scripts that are no longer needed for individual packages.

Testing

This change was tested using:

• [ ] WDIO
• [x] Jest
• [ ] Visual testing (please attach a screenshot or recording)
• [x] Other (please describe below)
• [ ] No tests are needed

This was tested by installing it locally in terra-framework e.g.

After the changes, the packages were able to be installed again:

Terra-framework:

Terra-toolkit:

Reviews

In addition to engineering reviews, this PR needs:

• [ ] UX review
• [ ] Accessibility review
• [ ] Functional review

Additional Details

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Thank you for contributing to Terra. @cerner/terra