Remove GitLFS and Jupyter from Package stage

Describe the change and rationale here.

In January 2020, we made a change to add Jupyter Notebooks and Git LFS categories to the Package stage. This was done as per gitlab-org/gitlab#55372 (closed) and gitlab-org/gitlab#55362 (closed), but we did not follow the approval process for making category changes.

This was noticed by @markpundsack via slack and suggested that we open an MR removing the categories and follow the process to drive discussion.

This MR removes the categories and their respective direction pages.

Approvals

Merge requests with changes to stages and groups and significant changes to categories need to be created, approved, and/or merged by each of the below:

• EVP of Product
• VP of Product Strategy
• The Product Director relevant to the stage group(s)
• The Engineering Director relevant to the stage group(s)
• CEO

The following people need to be on the merge request so they stay informed:

• EVP of Engineering @edjdev
• Senior Director of Development @clefelhocz1
• Director of Quality @meks
• The Product Marketing Manager relevant to the stage group(s)