Make pytest-celery package install configurable in worker Dockerfile

[Nusnus]

Added PYTEST_CELERY_PKG build arg to the worker Dockerfile, defaulting to 'pytest-celery' (PyPI). This allows CI and users to override the install source, e.g. to install from a specific branch:

PYTEST_CELERY_PKG='pytest-celery@git+https://github.com/celery/pytest-celery.git@my-branch'

• Added PYTEST_CELERY_PKG ARG to Dockerfile (default: pytest-celery)
• Added DEFAULT_WORKER_PYTEST_CELERY_PKG constant
• Added pytest_celery_pkg() classmethod to CeleryWorkerContainer
• Added default_worker_pytest_celery_pkg fixture
• Wired into buildargs() and celery_base_worker_image build fixture

[auvipy]

looks good

[Copilot]

Pull request overview

Adds a configurable PYTEST_CELERY_PKG build argument so the built-in worker image can install pytest-celery from PyPI by default or from an alternate source (e.g., a git ref) in CI/custom setups.

Changes:

• Introduces DEFAULT_WORKER_PYTEST_CELERY_PKG and threads it through CeleryWorkerContainer.buildargs().
• Adds a session fixture default_worker_pytest_celery_pkg and wires it into the worker image build args.
• Updates CI workflows to set PYTEST_CELERY_PKG to install pytest-celery from the current repo.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/unit/vendors/test_worker/test_worker.py	Updates buildargs unit test to include PYTEST_CELERY_PKG.
src/pytest_celery/vendors/worker/fixtures.py	Adds default_worker_pytest_celery_pkg fixture and passes it into celery_base_worker_image build args.
src/pytest_celery/vendors/worker/defaults.py	Adds DEFAULT_WORKER_PYTEST_CELERY_PKG defaulting from PYTEST_CELERY_PKG env var.
src/pytest_celery/vendors/worker/container.py	Adds pytest_celery_pkg() and includes it in buildargs().
src/pytest_celery/vendors/worker/Dockerfile	Adds ARG PYTEST_CELERY_PKG and installs it via pip during image build.
src/pytest_celery/init.py	Exposes the new fixture when the worker vendor is installed.
.github/workflows/python-package.yml	Sets PYTEST_CELERY_PKG for CI runs.
.github/workflows/examples.yml	Sets PYTEST_CELERY_PKG for examples CI runs.

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[codecov]

Codecov Report

❌ Patch coverage is 11.11111% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 23.71%. Comparing base (c045029) to head (34f0886).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/pytest_celery/vendors/worker/container.py	25.00%	3 Missing ⚠️
src/pytest_celery/vendors/worker/fixtures.py	0.00%	3 Missing ⚠️
src/pytest_celery/__init__.py	0.00%	1 Missing ⚠️
src/pytest_celery/vendors/worker/defaults.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #475      +/-   ##
==========================================
- Coverage   23.80%   23.71%   -0.09%     
==========================================
  Files          41       41              
  Lines        1294     1303       +9     
  Branches       78       78              
==========================================
+ Hits          308      309       +1     
- Misses        959      967       +8     
  Partials       27       27              

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