feat(opt): Reduce array cloning by initializing refcounts to 0, not 1

[jfecher]

Description

Problem*

Summary*

I noticed after storing an array in a variable we were always issuing an inc_rc which lead to arrays having an rc of 2 to begin with instead of 1, meaning the first mutation would always be cloned.

Additional Context

Documentation*

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[jfecher]

This PR requires #6585 first

[jfecher]

Closing in favor of #6685