Remove the '--editable' pip flag for prod Dockerfile

[alikins]

What is this PR doing:

Remove the '--editable' pip flag for prod

Introduced in 63179d0984a75f9689401940dd6078160bc2cd62 but presumably not needed now.

Issue: No-Issue

Reviewers must know:

Notes:

PR Author: Add a QE reviewer (exceptions); Reviewers: look for sound code, no code smells, docs & test coverage Merger: When merging, include the Jira issue link in the squashed commit

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[rochacbruno]

This CI failure I think is solvable by rebasing against master

[newswangerd]

Closing stale PR