otelgin: update error handling to set attributes instead of recording errors

[flc1125]

Adjust position: https://github.com/open-telemetry/opentelemetry-go-contrib/blob/9bd144ac077475799793d0bad6e19f50d1aab5e1/instrumentation/github.com/gin-gonic/gin/otelgin/gin.go#L124C10-L124C21
Reference implementation: #8386

Originally posted by @pellared in #8408 (comment)

[Eshaan-byte]

Hi @flc1125 can i work on this issue? Thank you!