Redis v6.2 will reach end-of-life on July 30

[ocofaigh]

Redis v6.2 will reach end-of-life on July 30:
https://cloud.ibm.com/docs/cloud-databases?topic=cloud-databases-versioning-policy

Action: Remove support for v6.2 from module and DA

[shemau]

With only one valid version, the variable could be removed entirely. However, for consistency with other ICD and to allow a new value to be added later, the variable can remain in place with a single valid value.

I chose the second option, retaining the variable.