bump golang to 1.21.4

[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

Merging #19601 (2a27831) into main (553c85e) will decrease coverage by 0.02%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #19601      +/-   ##
==========================================
- Coverage   67.52%   67.50%   -0.02%     
==========================================
  Files         991      991              
  Lines      109144   109144              
  Branches     2719     2719              
==========================================
- Hits        73704    73683      -21     
- Misses      31467    31491      +24     
+ Partials     3973     3970       -3     

Flag	Coverage Δ
unittests	67.50% <ø> (-0.02%)	⬇️

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see 12 files with indirect coverage changes

[wy65701436]

lgtm