Update benchmarking scripts to work with the latest version of PyBaMM

[Saransh-cpp]

Cleaned up a bit and the repo is up again! The following scripts have gone stale and do not work anymore -

pybamm-validation/.github/workflows/work_precision_sets.yml

Lines 8 to 14 in 2d78925

	# python benchmarks/work_precision_sets/time_vs_dt_max.py
	# python benchmarks/work_precision_sets/time_vs_mesh_size.py
	# python benchmarks/work_precision_sets/time_vs_no_of_states.py
	# python benchmarks/work_precision_sets/time_vs_reltols.py
	# python benchmarks/work_precision_sets/time_vs_abstols.py
	# python benchmarks/work_precision_sets/comsol_comparison.py
	# python benchmarks/work_precision_sets/ecker_comparison.py

I have not been following developments in PyBaMM's API, so I cannot fix these 😬

Tagging @pybamm-team/maintainers (if someone has spare time) here because this repository is not watched by everyone.