fix: dont utilize the default efs mount on normal aws deploys

[tayritenour]

Ticket

Description

Normal det deploys were broken with this default set. It didn't seem necessary in the original PR, but we had to unset this again to not pollute other deploys.

This caused the parameter to leak into normal aws deploys which isn't valid

Test Plan

Checklist

• Changes have been manually QA'd
• User-facing API changes need the "User-facing API Change" label.
• Release notes should be added as a separate file under docs/release-notes/.
  See Release Note for details.
• Licenses should be included for new code which was copied and/or modified from any external code.

[netlify]

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Name	Link
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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 48.60%. Comparing base (9abde37) to head (aca169e).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9437      +/-   ##
==========================================
- Coverage   48.60%   48.60%   -0.01%     
==========================================
  Files        1233     1233              
  Lines      158981   158981              
  Branches     2778     2777       -1     
==========================================
- Hits        77268    77267       -1     
- Misses      81539    81540       +1     
  Partials      174      174              

Flag	Coverage Δ
backend	42.14% <ø> (-0.01%)	⬇️
harness	64.02% <ø> (ø)
web	44.38% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
harness/determined/deploy/aws/cli.py	16.86% <ø> (ø)

... and 4 files with indirect coverage changes