Datadog update env clobbering behavior

[ericmustin]

Description:

Sometimes users will set both a deployment.environment (the opentelemetry semantically correct way to define an environment attribute) attribute and an env attribute (the datadog way to define an environment span tag) on the same application, but they will have different values. This creates a variety of unintended behaviors within the Datadog UI, which correctly uses deployment.environment values for most critical details, but hardcodes some links to other views using the env value, leading confusing behavior. for the sake of a coherent experience, it makes sense to ensure these span tags are always set to the same value (the deployment.environment) even if that means clobbering the original env value.

Link to tracking Issue: n/a

Testing: added a unit test

Documentation: adding docs to the Datadog docs/onboarding page encouraging users to rely on the opentelemetry best practice deployment.environment only. cc @mx-psi

[mx-psi]

Looks good, just two minor comments

[bogdandrutu]

golangci-lint run --allow-parallel-runners
translate_traces_test.go:1424: File is not `gofmt`-ed with `-s` (gofmt)
		"env":                    pdata.NewAttributeValueString("incorrectenv"),
make[1]: *** [../../Makefile.Common:93: lint] Error 1

[mx-psi]

@ericmustin see comment above

need to gofmt

[ericmustin]

@mx-psi @bogdandrutu sorry about that, should be good to go now (would love to get this in v0.29.0 if you don't mind)

[ericmustin]

@jchengsfx @bogdandrutu it would be great to get this in for v0.29.0 if possible