Clear host_mdm table row when existing Windows hosts enroll as a different OS (#28463)

For https://github.com/fleetdm/fleet/issues/27501 . We wanted the fix to
be as simple and targeted as possible so I made it only happen when an
existing Windows host enrolls as a different OS.

# Checklist for submitter

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changes/27501-clear-windows-mdm-info-on-linux-enroll

@@ -0,0 +1 @@
+Windows hosts which re-enroll as another OS such as Linux will no longer show Windows MDM information on the hosts page unless they later re-enroll as a Windows host again(i.e. when dual booting).