New redis v2 license

[pombredanne]

https://redis.com/legal/rsalv2-agreement/

See also rq/rq#2062

[DennisClark]

Note that we already have https://scancode-licensedb.aboutcode.org/rsalv2.html
Redis changed the license text on 2023-12-30 without bumping up the license version number.
We just need to update the license text.

[DennisClark]

we will need to add rules for the various older versions

[pombredanne]

@DennisClark for reference these are somewhat different texts. See attached:

• rsalv2-2022-11-15.txt

• rsalv2-2023-12-30.txt

• and the diff https://gist.github.com/pombredanne/5753f4daa693a14178dced88db652ad2/revisions