Add --break-system-packages when using --target

[chennes]

Fixes #8

[Copilot]

Pull Request Overview

This PR adds the --break-system-packages flag to pip commands when installing to a specific target directory outside of system containers. The change addresses pip's restriction on installing packages to custom directories when not in a virtual environment.

• Adds conditional logic to append --break-system-packages when --target or --path options are present
• Only applies this flag when not using system pip installation locations (i.e., outside containers/virtual environments)

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[Copilot]

The --break-system-packages flag is being added even if it already exists in the args list, which could result in duplicate flags. Consider checking if the flag is already present before appending it.

Suggested change

	elif "--target" in args or "--path" in args:
	# If we are not running in some sort of container, and are instead trying to install to a
	# specific directory, pip will complain because it doesn't know that we're effectively
	# using this as a virtual env: it's not accessible to non-FreeCAD installations (at least,
	# not without some extra work on the user's part). So add the --break-system-packages flag
	# so pip will allow us to write to the --target directory
	args.append("--break-system-packages")
	if "--break-system-packages" not in args:
	args.append("--break-system-packages")

[github-actions]

Successfully created backport PR for main:

• [Backport main] Add --break-system-packages when using --target #219

[github-actions]

Backport failed for main, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin main
git worktree add -d .worktree/backport-218-to-main origin/main
cd .worktree/backport-218-to-main
git switch --create backport-218-to-main
git cherry-pick -x 48a0e1f9d6f90bd3cef82c4ea45d1a44e3abaaff