Limit the number of bytes read from the zpages body

[dmathieu]

This is part of the golangci-lint upgrade: #8648

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.1%. Comparing base (73e1790) to head (513bf60).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #8656   +/-   ##
=====================================
  Coverage   82.1%   82.1%           
=====================================
  Files        182     182           
  Lines      13776   13777    +1     
=====================================
+ Hits       11318   11321    +3     
+ Misses      2054    2053    -1     
+ Partials     404     403    -1     

Files with missing lines	Coverage Δ
zpages/tracez.go	55.2% <100.0%> (+0.3%)	⬆️

... and 1 file with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.