Follow-up from "Add pagination frontend to Environments dashboard" - use httpStatusCodes

The following discussion from !39637 (merged) should be addressed:

• @blabuschagne started a discussion: (+1 comment)

  Suggestion: We should utilise httpStatusCodes for these static values.

  Ref: https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/assets/javascripts/lib/utils/http_status.js#L5