Rotation of MC events for signal event generation does not preserve relative declination difference between true and reco directions

[martwo]

The rotation function

skyllh/skyllh/core/utils/coords.py

Line 6 in 130652f

def rotate_spherical_vector(ra1, dec1, ra2, dec2, ra3, dec3):

does not preserve the relative declination difference between true and reco directions.
This function is used in the class PointLikeSourceI3SignalGenerationMethod:

skyllh/skyllh/i3/signal_generation.py

Line 95 in 130652f

class PointLikeSourceI3SignalGenerationMethod(SignalGenerationMethod):