d/control: Move apt-config-icons-hidpi to Recommends

We want to support HiDPI displays out-of-box.
5 jobs for hidpi in 6 minutes and 12 seconds (queued for 1 second)
Status Job ID Name Coverage
  Package
passed #367939
librem5
package-pureos-byzantium

00:01:51

passed #367940
librem5:arm64
package-pureos-byzantium:arm64

00:06:09

 
  Test Package
passed #367941
librem5
autopkgtest-pureos-byzantium-package

00:00:52

passed #367943
librem5
check-tarball

00:00:43

passed #367942
librem5
lintian-pureos-byzantium-package

00:00:38