tests(otelgin): move test files and trim module dependencies

[flc1125]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 66.9%. Comparing base (7a12292) to head (5699ce0).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #6360   +/-   ##
=====================================
  Coverage   66.9%   66.9%           
=====================================
  Files        193     193           
  Lines      15652   15652           
=====================================
+ Hits       10479   10482    +3     
+ Misses      4882    4880    -2     
+ Partials     291     290    -1     

Files with missing lines	Coverage Δ
...ation/github.com/gin-gonic/gin/otelgin/gintrace.go	84.0% <ø> (ø)

... and 1 file with indirect coverage changes

---- 🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests

[dmathieu]

Not having b3 as a dependency of the instrumentation anymore is nice.