[build] remove maintainer password from PyPI publish workflow in lieu of trusted publisher attestation

[zacharyburnett]

Resolves SCSB-199

• add a Trusted Publisher configuration to the PyPI project by visiting https://pypi.org/manage/project/stpipe/settings/publishing/?provider=github&owner=spacetelescope&repository=stpipe&workflow_filename=build.yml
• remove pypi_token (STScI PyPI maintainer password) from build workflow
• wait for issue with reusable workflows to be resolved in pypa/warehouse

Tasks

• update or add relevant tests
• update relevant docstrings and / or docs/ page
• Does this PR change any API used downstream? (if not, label with no-changelog-entry-needed)
  • write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see below for change types)
  • run regression tests with this branch installed ("git+https://github.com/<fork>/stpipe@<branch>")
    • jwst regression test
    • romancal regression test

news fragment change types...

• changes/<PR#>.feature.rst: new feature
• changes/<PR#>.bugfix.rst: fixes an issue
• changes/<PR#>.doc.rst: documentation change
• changes/<PR#>.removal.rst: deprecation or removal of public API
• changes/<PR#>.misc.rst: infrastructure or miscellaneous change

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.38%. Comparing base (76ffd67) to head (d6e6cd2).
Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #223   +/-   ##
=======================================
  Coverage   95.38%   95.38%           
=======================================
  Files          37       37           
  Lines        3251     3251           
=======================================
  Hits         3101     3101           
  Misses        150      150           

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