fix: python requirements for pytest and moto

[erikwilson]

Description

Resolve some issues with recently released python modules by pinning to older versions.

Test Plan

Automated testing.

Commentary (optional)

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.

Ticket

[netlify]

✅ Deploy Preview for determined-ui canceled.

Name	Link
🔨 Latest commit	37633fc
🔍 Latest deploy log	https://app.netlify.com/sites/determined-ui/deploys/65b7dfcc87dd7e0008d5c3a4

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (78929c0) 44.46% compared to head (37633fc) 47.42%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8769      +/-   ##
==========================================
+ Coverage   44.46%   47.42%   +2.96%     
==========================================
  Files         916     1047     +131     
  Lines      156662   166976   +10314     
  Branches     2242     2240       -2     
==========================================
+ Hits        69652    79184    +9532     
- Misses      86851    87633     +782     
  Partials      159      159              

Flag	Coverage Δ
backend	41.84% <ø> (ø)
harness	64.36% <ø> (+10.22%)	⬆️
web	42.50% <ø> (ø)

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

see 192 files with indirect coverage changes