fix: handle pinned Ape plugins in build generation

[sanjaysudagani]

What I did

Updated generated Dockerfiles so Silverback does not call ape plugins install -U . when project Ape plugins are version-pinned.

fixes: #220

How I did it

• inspected Ape project config for pinned plugin versions in ape-config.yaml and pyproject.toml
• generated ape plugins install . for pinned-plugin projects
• preserved ape plugins install -U . for unpinned projects
• added regression tests for both supported config formats
• documented the pinned-plugin behavior in the deployment guide

How to verify it

. .venv/bin/activate && pytest tests/test_utils.py -q
. .venv/bin/activate && ruff check silverback/_build_utils.py tests/test_utils.py
. .venv/bin/activate && ruff format --check silverback/_build_utils.py tests/test_utils.py

Then review docs/userguides/deploying.md for the pinned-plugin deployment note.

Checklist

• Passes all linting checks (pre-commit and CI jobs)
• New test cases have been added and are passing
• Documentation has been updated
• PR title follows Conventional Commit standard (will be automatically included in the changelog)

[fubuloubu]

This is a great fix!

I also think that an additional fix could be added upstream to ape plugins install so that it would function correctly w/ pinned dependencies with or without --upgrade