Update CI Upstream workflow to remove branch triggers

[hutch3232]

Removed redundant push and pull_request triggers from CI workflow. The same uv run pytest is triggered on PRs with master and post-merge as in the Unit Tests CI. Removing those triggers so that they only execute on chron trigger and manual trigger.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.05%. Comparing base (aa949dc) to head (5bcbad5).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #646   +/-   ##
=======================================
  Coverage   85.05%   85.05%           
=======================================
  Files          85       85           
  Lines        4865     4865           
  Branches      619      619           
=======================================
  Hits         4138     4138           
  Misses        518      518           
  Partials      209      209           

Flag	Coverage Δ
unittests	85.05% <ø> (ø)

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