[ENT-9541] Revert learner pathway skeleton implementation (PR #30355)

[mahamakifdar19]

Ticket
https://2u-internal.atlassian.net/browse/ENT-9541

Description
This PR reverts the changes made in PR #30355.

Note: Please refer to the Support Development Guidelines on the wiki page to consider backporting to active releases:
https://openedx.atlassian.net/wiki/spaces/COMM/pages/4248436737/Support+Guidelines+for+active+releases

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[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX staging environment in preparation for a release to production.

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX production environment.

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX production environment.