MAINTAINERS: remove myself as a Xen maintainer

I am no longer actively involved in the Xen Project.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Message-id: 20260224112215.83355-1-paul@xen.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

MAINTAINERS

@@ -619,7 +619,6 @@ Guest CPU Cores (Xen)
 X86 Xen CPUs
 M: Stefano Stabellini <sstabellini@kernel.org>
 M: Anthony PERARD <anthony@xenproject.org>
-M: Paul Durrant <paul@xen.org>
 M: Edgar E. Iglesias <edgar.iglesias@gmail.com>
 L: xen-devel@lists.xenproject.org
 S: Supported