fix: assign metas to key and value

[zyyw]

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Comprehensive Summary of your change

Issue being fixed

Fixes #20120

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• 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

Attention: Patch coverage is 0% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 67.38%. Comparing base (c2cb8ea) to head (f2b3114).

Additional details and impacted files

@@                Coverage Diff                @@
##           release-2.8.0   #20127      +/-   ##
=================================================
- Coverage          67.38%   67.38%   -0.01%     
=================================================
  Files                984      984              
  Lines             107093   107094       +1     
  Branches            2671     2671              
=================================================
- Hits               72167    72165       -2     
- Misses             31046    31051       +5     
+ Partials            3880     3878       -2     

Flag	Coverage Δ
unittests	67.38% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/server/v2.0/handler/project_metadata.go	0.00% <0.00%> (ø)

... and 4 files with indirect coverage changes

[chlins]

lgtm