fix(otelgin,otelecho): use MetricAttributes.Route

[gaiaz-iusipov]

Minor changes in the components:

• go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin
• go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho

Not sure whether it’s necessary to update the changelog.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@c6f5e27). Learn more about missing BASE report.
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff           @@
##             main   #8677   +/-   ##
======================================
  Coverage        ?   82.1%           
======================================
  Files           ?     183           
  Lines           ?   13790           
  Branches        ?       0           
======================================
  Hits            ?   11332           
  Misses          ?    2054           
  Partials        ?     404           

Files with missing lines	Coverage Δ
...umentation/github.com/gin-gonic/gin/otelgin/gin.go	92.8% <100.0%> (ø)
...entation/github.com/labstack/echo/otelecho/echo.go	100.0% <100.0%> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.