otlptracehttp, otlpmetrichttp: Retry temporary HTTP request failures

[pellared]

Fixes #4663

[codecov]

Codecov Report

Merging #4679 (131a2d9) into main (aea3eab) will increase coverage by 0.0%.
The diff coverage is 100.0%.

@@          Coverage Diff          @@
##            main   #4679   +/-   ##
=====================================
  Coverage   81.6%   81.6%           
=====================================
  Files        225     225           
  Lines      17983   17991    +8     
=====================================
+ Hits       14682   14694   +12     
+ Misses      3001    2997    -4     
  Partials     300     300           

Files	Coverage Δ
exporters/otlp/otlpmetric/otlpmetrichttp/client.go	80.4% <100.0%> (+1.6%)	⬆️
exporters/otlp/otlptrace/otlptracehttp/client.go	76.5% <100.0%> (-1.1%)	⬇️

... and 2 files with indirect coverage changes