Hello,
Why you want que .la files ? do we need it ?

Thank you

@sergiomb yes, the library needs the .la files of the coders.

Example, from strace output of display some_image.jpg

readlink("/usr/lib64/ImageMagick-7.1.0/modules-Q16HDRI/coders/jpeg.la", 0x7ffd475557a0, 1023) = -1 EINVAL (Argument invalide)
newfstatat(AT_FDCWD, "/usr/lib64/ImageMagick-7.1.0/modules-Q16HDRI/coders/jpeg.la", {st_mode=S_IFREG|0644, st_size=1111, ...}, 0) = 0
access("/usr/lib64/ImageMagick-7.1.0/modules-Q16HDRI/coders/jpeg.la", F_OK) = 0
openat(AT_FDCWD, "/usr/lib64/ImageMagick-7.1.0/modules-Q16HDRI/coders/jpeg.la", O_RDONLY) = 4
openat(AT_FDCWD, "/usr/lib64/ImageMagick-7.1.0/modules-Q16HDRI/coders/jpeg.so", O_RDONLY|O_CLOEXEC) = 4

And if the jpeg.la file is missing, image is not displayed

More importantly, including la files is against the packaging policy https://docs.fedoraproject.org/en-US/packaging-guidelines/#packaging-static-libraries

This is not forbiden by Guidelines

Libtool archives, foo.la files, SHOULD NOT be included. 

This is not a must ;)
ImageMagick is obviously an exception, because really required and used

OK . accepted