linux_testing: 6.13-rc7 -> 6.14-rc1

pkgs/os-specific/linux/kernel/kernels-org.json

···
 {
     "testing": {
-        "version": "6.13-rc7",
-        "hash": "sha256:12c9bd0ikppkdpqmvg7g2062s60ks9p0qxx1jis29wl9swr74120"
+        "version": "6.14-rc1",
+        "hash": "sha256:0schcgij7kdzj0zb6g3sjf32mq7s388hysrfzjzi5g1y3py21igk"
     },
     "6.1": {
         "version": "6.1.128",