Make WithoutTimestamps work

[luxas]

Hi! I noticed there's no handling for the WithoutTimestamps option in the stdouttrace package, so I've fixed that now :)

Thanks for looking at this. Maybe this can still be merged before v1.0.0, in order to not have clients depending on WithoutTimestamps doing nothing?

Thanks for this great project, really enjoying using OpenTelemetry 😄

[codecov]

Codecov Report

Merging #2195 (6138c46) into main (85c27e0) will increase coverage by 0.0%.
The diff coverage is 100.0%.

@@          Coverage Diff          @@
##            main   #2195   +/-   ##
=====================================
  Coverage   72.8%   72.9%           
=====================================
  Files        177     177           
  Lines      12151   12161   +10     
=====================================
+ Hits        8852    8869   +17     
+ Misses      3060    3054    -6     
+ Partials     239     238    -1     

Impacted Files	Coverage Δ
exporters/stdout/stdouttrace/trace.go	75.6% <100.0%> (+7.8%)	⬆️
...s/otlp/otlptrace/internal/connection/connection.go	16.4% <0.0%> (+1.5%)	⬆️
exporters/stdout/stdouttrace/config.go	100.0% <0.0%> (+17.3%)	⬆️