Pull Request check-list

• Do tests and lints pass with this change?
• Do the CI tests pass with this change (enable it first in your forked repo and wait for the github action build to finish)?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)?
• Is the new or changed code fully tested?
• Is there an example added to the examples folder (if applicable)?

Description of change

The FT.DEL and FT.MGET commands are not supported in RediSearch 2.0+. Most of the other RediSearch 1.0-speific commands had already been marked as deprecated, I'm guessing these two were missed.

TODO: Check if we need to document the deprecation.