fedora-intune: use Himmelblau instead of the Microsoft Intune app

Go with Entra ID sign-in through Himmelblau for fedora-intune and drop
the Microsoft Intune app (intune-portal, identity broker) variant. With
a single image, the workstation, Edge and Defender manifests move back
from images/shared into images/fedora-intune, and CI builds just that
image again. The Microsoft repo is now limited to mdatp and Edge.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

images/fedora-intune/files/himmelblau.conf

@@ -0,0 +1,17 @@
+# Himmelblau configuration. See himmelblau.conf(5) and
+# https://himmelblau-idm.org/docs/reference/himmelblau-conf/
+#
+# No tenant settings are needed: `domain` defaults to the domain of the first
+# user who signs in, and that user joins the device to Entra ID. Restrict who
+# may sign in with pam_allow_groups (group object IDs or UPNs).
+
+[global]
+# Enroll the device in Intune and apply/report compliance policies.
+apply_policy = true
+# Fedora's admin group; members of sudo_groups (Entra group object IDs) are
+# added to it.
+local_sudo_group = wheel
+# Home directories named after the account (e.g. /home/jdoe), with a UPN alias.
+home_attr = CN
+home_alias = SPN
+use_etc_skel = true