fix(sub level): insert sub level into correct pos in HummockVersion

[soundOfDestiny]

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What's changed and what's your intention?

port #9600

Checklist For Contributors]

• I have demonstrated that backward compatibility is not broken by breaking changes and created issues to track deprecated features to be removed in the future. (Please refer to the issue)
• All checks passed in ./risedev check (or alias, ./risedev c)

Checklist For Reviewers

• I have requested macro/micro-benchmarks as this PR can affect performance substantially, and the results are shown.

Documentation

• My PR DOES NOT contain user-facing changes.

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Release note