Replace bare except statements

[ClaraBuettner]

flake8 tests for "Can not use bare except" are currently excluded. I tried to fix those problems, but since I didn't know the error that could show up for all occurrences, I was not able to fix all of them. It would be good if I could get some help from the others who created those statements.

These statements occur e.g. here:

eTraGo/etrago/cluster/electrical.py

Lines 969 to 973 in e16bdd3

	try:
	cf = fixed_capacity_fac[gen["carrier"]]
	except:
	print(gen)
	cf = 1

You can easily find them when running flake8 .
When these problems are solved, we can turn on the flake8 changes for this in noxfile.py.