MAINTAINERS: replace Taras Chornyi with Elad Nachman for Marvell Prestera

We have not seen emails or tags from Taras in over 5 years,
and there is no recent mailing list activity.
Elad Nachman has been providing reviews in the last couple
of years and is the top reviewer for this subsystem.

Subsystem MARVELL PRESTERA ETHERNET SWITCH DRIVER
  Changes 39 / 157 (24%)
  (No activity)
  Top reviewers:
    [8]: enachman@marvell.com
    [6]: horms@kernel.org
    [4]: idosch@nvidia.com
    [3]: andrew@lunn.ch
    [3]: jacob.e.keller@intel.com
    [3]: jiri@nvidia.com
  INACTIVE MAINTAINER Taras Chornyi <taras.chornyi@plvision.eu>

Link: https://patch.msgid.link/20260303215339.2333548-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

MAINTAINERS

@@ -15483,7 +15483,7 @@ S:	Supported
 F:	drivers/perf/marvell_pem_pmu.c
 
 MARVELL PRESTERA ETHERNET SWITCH DRIVER
-M:	Taras Chornyi <taras.chornyi@plvision.eu>
+M:	Elad Nachman <enachman@marvell.com>
 S:	Supported
 W:	https://github.com/Marvell-switching/switchdev-prestera
 F:	drivers/net/ethernet/marvell/prestera/