[Enhancement] clean minor version of k8s

[yandongxiao]

Description

In cloud provider, the minor version may be like "28+" from alibaba cloud. So we need to remove the non-digit characters.

this is from alibaba cloud

{
  "major": "1",
  "minor": "28+",
  "gitVersion": "v1.28.3-aliyun.1",
  "gitCommit": "7b6ea506b6deb03bac7aaeb10f6ee0a99004b147",
  "gitTreeState": "clean",
  "buildDate": "2023-10-19T07:10:40Z",
  "goVersion": "go1.20.10",
  "compiler": "gc",
  "platform": "linux/amd64"
}

and this is from eks cloud

{
  "major": "1",
  "minor": "27",
  "gitVersion": "v1.27.8-gke.1067004",
  "gitCommit": "6f460c12ad45abb234c18ec4f0ea335a1203c415",
  "gitTreeState": "clean",
  "buildDate": "2024-01-04T22:48:32Z",
  "goVersion": "go1.20.11 X:boringcrypto",
  "compiler": "gc",
  "platform": "linux/amd64"
}

Checklist

For operator, please complete the following checklist:

• run make generate to generate the code.
• run golangci-lint run to check the code style.
• run make test to run UT.
• run make manifests to update the yaml files of CRD.