version: hard-coded max version guard can reject future upstream versions

[wlwilliamx]

What did you do?

I found that the new-architecture repo still hard-codes the max compatible versions for PD, TiKV and TiCDC in pkg/version/check.go:

• maxPDVersion = 15.0.0
• maxTiKVVersion = 15.0.0
• MaxTiCDCVersion = 15.0.0-alpha

This can make the version check reject future upstream versions even when there is no known incompatibility.

What did you expect to see?

The new architecture should keep the minimum compatible version checks, but it should not reject newer versions only because of a hard-coded upper bound.

What did you see instead?

Once upstream versions move past the hard-coded limit, TiCDC may report errors like:

• PD ... is not supported, only support version less than 15.0.0
• TiKV ... is not supported, only support version less than 15.0.0
• TiCDC ... is not supported, only support version less than 15.0.0-alpha

Versions of the cluster

Upstream TiDB cluster version (execute SELECT tidb_version(); in a MySQL client):

N/A - code issue in the version guard logic

Upstream TiKV version (execute tikv-server --version):

N/A - code issue in the version guard logic

TiCDC version (execute cdc version):

N/A - code issue in the version guard logic