add prepare migration script for 2.12.0

[MinerYang]

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Comprehensive Summary of your change

Issue being fixed

Fixes #(issue)

Please indicate you've done the following:

• Well Written Title and Summary of the PR
• Label the PR as needed. "release-note/ignore-for-release, release-note/new-feature, release-note/update, release-note/enhancement, release-note/community, release-note/breaking-change, release-note/docs, release-note/infra, release-note/deprecation"
• Accepted the DCO. Commits without the DCO will delay acceptance.
• Made sure tests are passing and test coverage is added if needed.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed in website repository.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 66.18%. Comparing base (c8c11b4) to head (04c2fcc).
Report is 288 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main   #21022       +/-   ##
===========================================
+ Coverage   45.36%   66.18%   +20.81%     
===========================================
  Files         244     1048      +804     
  Lines       13333   114469   +101136     
  Branches     2719     2856      +137     
===========================================
+ Hits         6049    75759    +69710     
- Misses       6983    34566    +27583     
- Partials      301     4144     +3843     

Flag	Coverage Δ
unittests	66.18% <ø> (+20.81%)	⬆️

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see 1287 files with indirect coverage changes

[wy65701436]

lgtm