[Chore] add UT for gen-disk-skus-map_test

[Zhupku]

This pull request includes a new test file for the gen-disk-skus-map tool. The change adds a basic test to ensure the main function runs without errors.

Testing:

• pkg/tool/gen-disk-skus-map_test.go: Added a new test file with a TestMain function to call the main function and verify it executes correctly.<!-- Thanks for sending a pull request! Here are some tips for you:

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What type of PR is this?

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Special notes for your reviewer:

Release note:

none

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: Zhupku
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[k8s-ci-robot]

Hi @Zhupku. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[andyzhangx]

this is not the right param