Make image scaling work without imagemagick support in eww

* lisp/net/shr.el (shr-rescale-image): Emacs has native image
scaling now, so images can be rescaled without imagemagick
support.
1 job for master in 51 minutes and 13 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #1760
test-all

00:51:13