Add autoflake to pre-commit config

[sea-bass]

I wanted this for removing unused imports, and indeed it caught one!

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
pyroboplan
__init__.py	0	0	100%
pyroboplan/core
__init__.py	0	0	100%
planning_context.py	8	8	0%	1, 4, 9, 13–15, 17–18
utils.py	134	12	91%	78–79, 81–84, 86–87, 228–229, 531, 542
pyroboplan/ik
__init__.py	0	0	100%
differential_ik.py	110	14	87%	193–194, 203–204, 232, 238, 244, 247, 293–294, 297–298, 303, 314
nullspace_components.py	35	0	100%
pyroboplan/models
__init__.py	0	0	100%
panda.py	45	0	100%
two_dof.py	25	13	48%	41, 47–49, 51, 57–59, 62, 65–68
ur5.py	15	15	0%	3–4, 6, 9, 18–20, 22, 25, 41–44, 46–47
utils.py	5	0	100%
pyroboplan/planning
__init__.py	0	0	100%
cartesian_planner.py	92	5	94%	115, 139, 143–144, 207
graph.py	130	4	96%	58, 103, 195, 261
graph_search.py	53	2	96%	57, 135
path_shortcutting.py	47	1	97%	120
prm.py	109	25	77%	113, 149, 211–214, 240–241, 247–248, 273–274, 278–279, 331–334, 337, 340, 348–350, 354–355
rrt.py	152	28	81%	157–158, 167–168, 192–193, 196, 204, 273, 302–303, 369, 417–419, 423–424, 428–431, 434, 437, 445–447, 450, 453
utils.py	47	0	100%
pyroboplan/trajectory
__init__.py	0	0	100%
polynomial.py	152	39	74%	148, 150–151, 153–155, 157–159, 162–185, 188, 191, 194, 203, 230, 299
trajectory_optimization.py	183	0	100%
trapezoidal_velocity.py	168	33	80%	283–284, 329, 331–335, 337–338, 341–359, 362–364, 373
pyroboplan/visualization
__init__.py	0	0	100%
meshcat_utils.py	21	13	38%	40–41, 43, 45, 57, 81–82, 109, 131–134, 136
TOTAL	1531	212	86%

Tests	Skipped	Failures	Errors	Time
97	0 💤	0 ❌	0 🔥	29.843s ⏱️