Drop libyui dependency in SLES (related to bsc#1254978)

[lslezak]

Problem

• The YaST packages used by Agama still require libyui libraries, that means we have to maintain them in the SLES16 product
• Related PR Initial implementation of dummy UI bindings yast-ycp-ui-bindings-dummy#1

Solution

• Update the dependencies so in SLES the yast2-ycp-ui-bindings-dummy package is used instead of the regular bindings.

Testing

• Tested manually

  • https://build.opensuse.org/project/show/systemsmanagement:Agama:branches:dummy-ui project builds the Agama installer ISO for openSUSE Tumbleweed (build log) and openSUSE Leap(build log), both logs show that the libyui is installed in the images (that's expected as both contain full YaST so we cannot drop the UI there)

  • https://build.suse.de/project/show/Devel:YaST:Agama:dummy-ui project (internal link) builds the SLES image, the libyui packages are not included in the image

[coveralls]

coverage: 41.883%. remained the same
when pulling 3dd65c2 on dummy-ui
into 730f9c3 on master.

[github-actions]

✅ Autosubmission job #21035050979 successfully finished
✅ Created submit request #1327424