PhoshHome: Don't set the width of the home bar

When setting 0 as width value, the compositor will set the width
automatically according to anchors.

This fixes an issue of folded home bar size not being updated after screen
rotation until it's unfolded.
5 jobs for home-width in 7 minutes and 21 seconds (queued for 27 seconds)
latest
Status Job ID Name Coverage
  Build
passed #113729
librem5
build:native

00:01:40

 
  Test
passed #113730
librem5
test:native

00:01:37

passed #113731
librem5
test:smoke:one-output

00:02:25

passed #113732
librem5
test:smoke:two-outputs

00:02:30

 
  Package
passed #113733
librem5
package:deb

00:01:27