They appear to be parallel lines at an angle of about 12 degrees off horizontal. In a quick check it doesn't appear they are noticeably curved. So in that case

They appear to be parallel lines at an angle of about 12 degrees off horizontal. In a quick check it doesn't appear they are noticeably curved. So in that case, a specific (small) region of the Fourier spectrum of that image should correspond to just those lines. So convert your image to Fourier space, locate the region (.. yeah, best to calculate where it should be, cause it won't really stand out enough to spot as the dashing is quite subtle), and then blur, or content-aware heal, or even just blacken the area. Convert back. Dashes gone. Easy as pi! cough