[landing] remove deprecated info blocks

Summary:
Removing old info blocks since we will be replacing them with new info blocks in subsequent diffs.

Depends on D8039

Test Plan:
Please see the demo videos to see that the old info blocks are no longer rendered:

Reviewers: atul, kamil

Reviewed By: atul

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8054