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/repos/microsoft.repo

@@ -0,0 +1,19 @@
+# packages.microsoft.com, limited with includepkgs to the packages the image
+# uses, 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=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