fix: a sha256 checking bug when downloading different versions of binary files

[24sama]

What type of PR is this?

/kind bug

What this PR does / why we need it:

fix: a sha256 checking bug when downloading different versions of binary files.
Now, the binaries will download into the subdirectory, which is the directory tree as:

xxxx/kubeadm/v1.24.8/amd64/kubeadm
xxxx/kubeadm/v1.24.8/arm64/kubeadm
xxxx/kubeadm/v1.25.0/amd64/kubeadm

Which issue(s) this PR fixes:

Fixes #

Special notes for reviewers:

Does this PR introduced a user-facing change?

Additional documentation, usage docs, etc.:

[ks-ci-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: 24sama

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• OWNERS [24sama]

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[pixiake]

/lgtm

[ks-ci-bot]

LGTM label has been added.

Git tree hash: 3b989912c817f4fb8d62d04ed59b783dce17eeac