dscim.diagnostics.stacked_damage_function.plot_stacked()'s "years" is a mutable default arg

[brews]

dscim.diagnostics.stacked_damage_function.plot_stacked()'s "years" has a mutable default arg. This is a common gotcha, we might want to refactor this to avoid bugs.

dscim/src/dscim/diagnostics/stacked_damage_function.py

Line 11 in 8a870c3

def plot_stacked(