sys-kernel/coreos-modules: disable CONFIG_NFS_V4_2_READ_PLUS

Disable CONFIG_NFS_V4_2_READ_PLUS kernel config, as
Linux kernel >= 6.6 enabled the CONFIG_NFS_V4_2_READ_PLUS config option
by default, and nfs-ganesha version <= 6.1 is broken due to mishandling
of the read_plus operation.

See:
nfs-ganesha/nfs-ganesha@24da5c3
See: flatcar/Flatcar#1565
See: nfs-ganesha/nfs-ganesha#1188

sdk_container/src/third_party/coreos-overlay/sys-kernel/coreos-modules/files/commonconfig-6.6

@@ -642,6 +642,7 @@ CONFIG_NFS_V3_ACL=y
 CONFIG_NFS_V4=m
 CONFIG_NFS_V4_1=y
 CONFIG_NFS_V4_2=y
+CONFIG_NFS_V4_2_READ_PLUS=n
 CONFIG_NFT_BRIDGE_META=m
 CONFIG_NFT_BRIDGE_REJECT=m
 CONFIG_NFT_COMPAT=m