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/shared/repos/microsoft.repo

@@ -1,19 +0,0 @@
-# packages.microsoft.com, limited with includepkgs to the packages the images
-# use, so nothing else from the RHEL repo can replace a Fedora package.
-
-[microsoft-rhel10]
-name=Microsoft Production (RHEL 10)
-baseurl=https://packages.microsoft.com/rhel/10/prod/
-enabled=1
-gpgcheck=1
-repo_gpgcheck=1
-gpgkey=https://packages.microsoft.com/keys/microsoft-2025.asc
-includepkgs=intune-portal microsoft-identity-broker mdatp
-
-[microsoft-edge]
-name=Microsoft Edge
-baseurl=https://packages.microsoft.com/yumrepos/edge/
-enabled=1
-gpgcheck=1
-gpgkey=https://packages.microsoft.com/keys/microsoft.asc
-includepkgs=microsoft-edge-stable