[packaging] Dev-only tools end up in install_requires

[skkzsh]

Issue

The following are dev-only tools introduced in #3039 and don't need to ship with the package:

changedetection.io/requirements.txt

Lines 157 to 159 in 7831a49

	ruff >= 0.11.2
	pre_commit >= 4.2.0
	dennis >= 1.2.0

Note

• The pytest family (pytest, pytest-flask, pytest-mock) is intentionally bundled per the explicit comment, so it's out of scope here:
  

  changedetection.io/requirements.txt

  Lines 95 to 98 in 7831a49

  	# Include pytest, so if theres a support issue we can ask them to run these tests on their setup
  	pytest ~=9.0
  	pytest-flask ~=1.3
  	pytest-mock ~=3.15

• pytest-xdist (L163) and psutil (L155, "Needed for testing") are similar candidates.

User impact

• Unnecessary transitive dependencies pulled into end-user environments (install size and time)
• Version conflicts with users who already pin ruff, pre_commit, or dennis

Example

For instance, in an LXC container provisioned by the Proxmox community script, the dev tool binaries land system-wide:

# which -a ruff pre-commit
/usr/local/bin/ruff
/usr/local/bin/pre-commit

Possible approach

These can live in a new requirements-dev.txt instead:

-r requirements.txt
ruff
pre_commit
dennis

Developers install them with pip install -r requirements-dev.txt.

Notes

Side note: pyproject.toml has [dependency-groups] for the same kind of split.