Add toolchain check

[cheese-head]

Fixes #5660

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.6%. Comparing base (74937a2) to head (c860c31).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #5983   +/-   ##
=====================================
  Coverage   84.6%   84.6%           
=====================================
  Files        272     272           
  Lines      22897   22897           
=====================================
+ Hits       19389   19391    +2     
+ Misses      3164    3162    -2     
  Partials     344     344           

see 1 file with indirect coverage changes

[pellared]

@cheese-head, can you do the same in https://github.com/open-telemetry/opentelemetry-go-contrib?