common: update_packages: add xfce image to excluded repos

Summary:
common: make-update: add xfce image to excluded repos

This adds the `solus-image-xfce` repo to the exclusion list for `make update`, same as for the other image repos
When this repo is part of the list users without team permissions get an error on `make clone`

This patch also updates the `packages` list with this and other changes

Test Plan:
1. Updated `packages` using `make update`
2. Confirmed `solus-image-xfce` was gone
3. Ran `make clone` without error

Reviewers: #triage_team, EbonJaeger

Reviewed By: EbonJaeger

Spies: EbonJaeger

Differential Revision: https://dev.getsol.us/D14295

common/Go/update_packages.go

@@ -42,6 +42,7 @@ var excludes = []string{
 	"solus-image-i3",
 	"solus-image-mate",
 	"solus-image-plasma",
+	"solus-image-xfce",
 	"solus-secureboot-keys",
 	"solus-site",
 	"solus-site-backend",

common/packages

@@ -3773,7 +3773,6 @@ python-zope.testing
 python2-importlib-metadata
 python2-packaging
 python2-pluggy
-python2-pytest
 python2-setuptools-scm
 python3
 python3-bsddb3
@@ -4136,7 +4135,6 @@ solid
 solidity
 solus-artwork
 solus-hardware-config
-solus-image-xfce
 solus-sc
 solvespace
 sonivox