fix Encode manipulator to make sure to interlace image if necessary

[konnng-dev]

Hi @Art4 ,

I made this additional change to make sure it will create interlaced PNGS / progressive JPGS if needed.

The old strategy I made was losing the interlace information when saving the image.

Background:

Sinve intervention v3 changed strategy about encoding image, it was necessary to create a new Image instance from scratch on Glide Encode manipulator.

On https://github.com/Art4/glide/blob/upgrade-to-glide-3/src/Manipulators/Encode.php#L49-L51

return (new ImageManager($driver))->read(
            $image->encodeByExtension($format, $quality)->toString()
        );

The read method will try to read the image using several Decoders until find the best suitable for it. When it finds, it will read the image blob. But there is a catch w/ Image Magick: when it reads back image, it will scratch any interlace info if present.

Solution:

Change the interlace checking after reading the encoded image, to make sure the interlaced information will persist.

[Art4]

Thank you. Please submit your changes as a new PR in the main repository.