Adding script for cgroup v2 memory available.sh (#41931)
* script for cgroup v2 memory available.sh
* Update content/en/docs/concepts/scheduling-eviction/node-pressure-eviction.md
Co-authored-by: Michael <haifeng.yao@daocloud.io>
* Update memory-available-cgroupv2.sh
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Co-authored-by: Michael <haifeng.yao@daocloud.io>