Hotfix: add pytz to api "prod" requirements

[NatSquared]

Issue #: N/A

Description of changes:
Hotfix an issue in cron where pytz was not being installed, causing crashes like the below.
This is because in api/setup.py, only prod.txt is installed as requirements for the api package.
Also upgrade pytz to 2026.1.post1 globally for consistency (BC has a new time zone!)

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.94%. Comparing base (a4e4b1c) to head (257e5c2).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2819      +/-   ##
==========================================
+ Coverage   75.43%   75.94%   +0.50%     
==========================================
  Files         519      556      +37     
  Lines       19877    20645     +768     
  Branches     1568     1568              
==========================================
+ Hits        14995    15678     +683     
- Misses       4876     4961      +85     
  Partials        6        6              

Flag	Coverage Δ
analyticsapi	88.93% <ø> (?)
api	86.05% <ø> (ø)

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see 37 files with indirect coverage changes

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud