ci: extend exclude list

Do not attempt to install qubes-gui-agent in dom0, as it depends on
qubes-core-vm which isn't available there.

Author: marmarek

.gitlab-ci.yml

@@ -9,4 +9,5 @@ include:
   project: QubesOS/qubes-continuous-integration
   ref: $CI_BRANCH_REF
 variables:
-  CI_INSTALL_EXCLUDE: pulseaudio-qubes
+  CI_INSTALL_EXCLUDE: pulseaudio-qubes pulseaudio-qubes-dbgsym
+  CI_INSTALL_EXCLUDE_DOM0: pulseaudio-qubes qubes-gui-agent