Migrate to semconv for otelecho

[Oloruntobi1]

Addresses the otelecho side comment in this issue:

#6919

[codecov]

Codecov Report

Attention: Patch coverage is 88.60606% with 94 lines in your changes missing coverage. Please review.

Project coverage is 76.3%. Comparing base (836e94b) to head (7bf0745).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
...abstack/echo/otelecho/internal/semconv/httpconv.go	88.4%	35 Missing and 14 partials ⚠️
...labstack/echo/otelecho/internal/semconv/v1.20.0.go	88.8%	13 Missing and 7 partials ⚠️
...com/labstack/echo/otelecho/internal/semconv/env.go	91.1%	11 Missing and 2 partials ⚠️
...om/labstack/echo/otelecho/internal/semconv/util.go	82.8%	10 Missing and 2 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #6980     +/-   ##
=======================================
+ Coverage   75.8%   76.3%   +0.5%     
=======================================
  Files        207     211      +4     
  Lines      19494   20312    +818     
=======================================
+ Hits       14786   15510    +724     
- Misses      4273    4342     +69     
- Partials     435     460     +25     

Files with missing lines	Coverage Δ
...entation/github.com/labstack/echo/otelecho/echo.go	100.0% <100.0%> (ø)
...om/labstack/echo/otelecho/internal/semconv/util.go	82.8% <82.8%> (ø)
...com/labstack/echo/otelecho/internal/semconv/env.go	91.1% <91.1%> (ø)
...labstack/echo/otelecho/internal/semconv/v1.20.0.go	88.8% <88.8%> (ø)
...abstack/echo/otelecho/internal/semconv/httpconv.go	88.4% <88.4%> (ø)

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[dmathieu]

You will need to add a changelog entry.

[dmathieu]

This needs a changelog entry (and to resolve the conflict).

[Oloruntobi1]

This needs a changelog entry (and to resolve the conflict).

Thanks. Done

[dmathieu]

Please run the test suite locally to ensure the CI doesn't fail.

[Oloruntobi1]

Please run the test suite locally to ensure the CI doesn't fail.

Yeah just did.