Feedback: Update certificates

[yoavredis]

Page https://redis.io/docs/latest/operate/rs/security/certificates/updating-certificates

Under section Update syncer certificates:

I think we can remove the following bullet, as version 6.0.20 or older are not supported anymore:
Known limitation: Updating syncer certificate on versions prior to 6.0.20-81 will restart the proxy and syncer connections. In these cases, we recommend scheduling certificate replacement carefully to minimize customer impact