openwrt-keyring: fix missing 24.10 usign key by installing it

openwrt-keyring: fix missing 24.10 usign key by installing it

@KA2107 reported that opkg is not able to verify the artifact signatures
produced by buildbot using the usign 24.10 release keys. So lets fix it
by actually adding the 24.10 usign key with d310c6f2833e97f7 fingerprint
into the openwrt-keyring package.

Fixes: #16850
Reported-by: @KA2107
Fixes: a535cfc09e1c ("openwrt-keyring: add OpenWrt 24.10 release build usign key")
Signed-off-by: Petr Štetiar <ynezz@true.cz>