[BD-05] Bug fix: TinyMCE version conflicts between ORA and edx-platform

[giovannicimolin]

TL;DR - This PR fixes TinyMCE prompt editor when the WYSIWYG editor is enabled in the responses field.

JIRA: JIRA-XXXX

What changed?

• [ More in depth breakdown of changes ]
• [ Peripheral things that got changed ]
• [ etc... ]

Developer Checklist

• Reviewed the release process
• Translations and JS/SASS compiled
• Bumped version number in setup.py and package.json

Testing Instructions

[ How should a reviewer test this PR? ]

Reviewer Checklist

Collectively, these should be completed by reviewers of this PR:

• I've done a visual code review
• I've tested the new functionality

FYI: @edx/masters-devs-gta

[openedx-webhooks]

Thanks for the pull request, @giovannicimolin! I've created BLENDED-777 to keep track of it in Jira. More details are on the BD-05 project page.

When this pull request is ready, tag your edX technical lead.