DRIVERS-2720: Update spec test's minServerVersion

[vbabanin]

Update spec test's minServerVersion due to the availability of bucketing options starting from version 6.3

Related server ticket: SERVER-67598 Related documentation: timeseries-procedures

Please complete the following before merging:

• [ ] Update changelog. (no changelog)
• [x] Make sure there are generated JSON files from the YAML test files.
• [x] Test changes in at least one language driver.
• [x] Test these changes against all server versions and topologies (including standalone, replica set, sharded clusters, and serverless).

[alcaeus]

Good point @dariakp! The original change was made in DRIVERS-2546. Looking at that ticket, most drivers have already finished the work required for it. With that in mind, if we want drivers to update their tests, a new ticket is required. @vbabanin can you please create a new DRIVERS ticket and link this PR to it? Thanks!