[Due for payment 2025-04-23] [Side Panel] Remove `newDotHelpSidePanel` beta, restore previous logic

[francoisl]

Coming from https://expensify.slack.com/archives/C07NZ8B1VTQ/p1744318812379879?thread_ts=1743366781.999989&cid=C07NZ8B1VTQ, it has been decided not to use the beta.

Task

Remove the part of the logic from #59221 that changes how we decide to show the help button based on the beta newDotHelpSidePanel, and start using the Onyx key nvp_sidePanel again.

cc @blazejkustra - tentatively assigning to you for now in case you can make this change in the next PR you must alredy be working on.

[brunovjk]

If we want to create a separate PR, I can review it, no payment required, as it is a simple revert.

[francoisl]

Sounds good, thanks. Assigning you as a C+ then.

[francoisl]

FYI I'll go ahead and submit a revert shortly.