MAINTAINERS: Remove Jianjun Wang as PCIe mediatek maintainer

Email to Jianjun Wang <jianjun.wang@mediatek.com> bounces with error:
"550 Relaying mail to jianjun.wang@mediatek.com is not allowed".
Remove the address to avoid sending future kernel maintenance queries
to an unreachable destination.

The MediaTek PCIe driver remains supported by Ryder Lee.

Signed-off-by: Hans Zhang <18255117159@163.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260515153635.136054-1-18255117159@163.com

Author: Hans Zhang

MAINTAINERS

@@ -20700,7 +20700,6 @@ F:	drivers/pci/controller/dwc/pcie-intel-gw.c
 
 PCIE DRIVER FOR MEDIATEK
 M:	Ryder Lee <ryder.lee@mediatek.com>
-M:	Jianjun Wang <jianjun.wang@mediatek.com>
 L:	linux-pci@vger.kernel.org
 L:	linux-mediatek@lists.infradead.org (moderated for non-subscribers)
 S:	Supported