loader(dm): remove unused functions (#11444)

[ti-chi-bot]

This is an automated cherry-pick of #11444

What problem does this PR solve?

Issue Number: close #11445

What is changed and how it works?

as title

Check List

Tests

• No code

Questions

Will it cause performance regression or break compatibility?

Do you need to update user documentation, design documentation or monitoring documentation?

Release note

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: D3Hunter, lance6716

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[lance6716]

/retest

[lance6716]

/retest

[lance6716]

/retest

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Please upload report for BASE (release-8.1@739708f). Learn more about missing BASE report.

Additional details and impacted files

Components	Coverage Δ
cdc	61.7724% <0.0000%> (?)
dm	51.0643% <0.0000%> (?)
engine	63.4232% <0.0000%> (?)

Flag	Coverage Δ
unit	57.3975% <ø> (?)

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@@               Coverage Diff                @@
##             release-8.1     #11460   +/-   ##
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  Coverage               ?   57.3975%           
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  Files                  ?        853           
  Lines                  ?     125798           
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  Hits                   ?      72205           
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  Partials               ?       5396