Remove dup semconv support from HTTP packages

[dmathieu]

This is the first cleanup PR for the old semconv in HTTP libraries.
There will be (at least) another PR cleaning up the semconv package itself.

[codecov]

Codecov Report

Attention: Patch coverage is 86.46865% with 82 lines in your changes missing coverage. Please review.

Project coverage is 78.7%. Comparing base (b9a7621) to head (0fcaea7).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...abstack/echo/otelecho/internal/semconv/httpconv.go	87.5%	35 Missing and 12 partials ⚠️
...com/labstack/echo/otelecho/internal/semconv/env.go	78.5%	23 Missing ⚠️
...om/labstack/echo/otelecho/internal/semconv/util.go	82.8%	10 Missing and 2 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #7584     +/-   ##
=======================================
- Coverage   81.5%   78.7%   -2.9%     
=======================================
  Files        200     186     -14     
  Lines      18129   14807   -3322     
=======================================
- Hits       14793   11656   -3137     
+ Misses      2938    2803    -135     
+ Partials     398     348     -50     

Files with missing lines	Coverage Δ
...lei/go-restful/otelrestful/internal/semconv/env.go	78.5% <100.0%> (-13.2%)	⬇️
...umentation/github.com/gin-gonic/gin/otelgin/gin.go	93.2% <100.0%> (+0.1%)	⬆️
....com/gin-gonic/gin/otelgin/internal/semconv/env.go	78.5% <100.0%> (-13.2%)	⬇️
...ub.com/gorilla/mux/otelmux/internal/semconv/env.go	78.5% <100.0%> (-13.2%)	⬇️
...entation/github.com/labstack/echo/otelecho/echo.go	100.0% <100.0%> (ø)
...tp/httptrace/otelhttptrace/internal/semconv/env.go	78.5% <100.0%> (-13.2%)	⬇️
...entation/net/http/otelhttp/internal/semconv/env.go	78.5% <100.0%> (-13.2%)	⬇️
instrumentation/net/http/otelhttp/transport.go	95.0% <100.0%> (-0.1%)	⬇️
...om/labstack/echo/otelecho/internal/semconv/util.go	82.8% <82.8%> (ø)
...com/labstack/echo/otelecho/internal/semconv/env.go	78.5% <78.5%> (ø)
... and 1 more

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[dmathieu]

I know this is a quite large thing, and fixes some bits that were missed before (in echo and gin).

[flc1125]

instrumentation/github.com/labstack/echo/otelecho/echotest_test.go

Is there an extra "test" in this filename.

[flc1125]

No other issues, very nice.

[dmathieu]

instrumentation/github.com/labstack/echo/otelecho/echotest_test.go

Is there an extra "test" in this filename.

There is both echotest_test.go and echo_test.go. We may want to make things nicer, but not in this PR.

[flc1125]

There is both echotest_test.go and echo_test.go. We may want to make things nicer, but not in this PR.

Yeah, you're right. We can focus on resolving just this current PR.