Replace "which" with "command -v"

[yzxiu]

What type of PR is this?

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #
On certain machines with shells like zsh, errors may occur when using "if...which".
We can resolve this issue by replacing "which" with "command -v".

[qemu-41] ~ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Ubuntu 20.04.6 LTS"
[qemu-41] ~ uname -a
Linux qemu-41 5.4.0-144-generic #161-Ubuntu SMP Fri Feb 3 14:49:04 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

before:

08:16:14 UTC message: [qemu-43]
downloading image: kubesphere/pause:3.8
08:16:14 UTC message: [qemu-45]
downloading image: kubesphere/pause:3.8
08:16:14 UTC message: [qemu-43]
pull image failed: Failed to exec command: sudo -E /bin/bash -c "env PATH=$PATH crictl pull kubesphere/pause:3.8 --platform amd64" 
env: ‘crictl’: No such file or directory: Process exited with status 127
08:16:14 UTC message: [qemu-42]
pull image failed: Failed to exec command: sudo -E /bin/bash -c "env PATH=$PATH crictl pull kubesphere/pause:3.8 --platform amd64" 
env: ‘crictl’: No such file or directory: Process exited with status 127
env: ‘crictl’: No such file or directory: Process exited with status 127

after:

Special notes for reviewers:

Does this PR introduced a user-facing change?

Additional documentation, usage docs, etc.:

[yzxiu]

@pixiake

[pixiake]

@yzxiu Thanks for this contribution!
/lgtm
/approve

[ks-ci-bot]

LGTM label has been added.

Git tree hash: c48db3823228beaf749eb2af93cc280269e2621e

[ks-ci-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pixiake, yzxiu

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[pixiake]

@all-contributors please add @yzxiu for code