linux_testing: 6.6-rc7 -> 6.7-rc1

ZSMALLOC is now the default allocator for ZSWAP, so if the allocator
isn't changed, ZSMALLOC must be y on 6.7 (and will default to that).
The script will set all options that can be modules to m anyway, so
there was no need for us to be explicitly setting it to module before
anyway.

pkgs/os-specific/linux/kernel/common-config.nix

···
       ZSWAP          = option yes;
       ZPOOL          = yes;
       ZBUD           = option yes;
-      ZSMALLOC       = module;
     };
 
     brcmfmac = {

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

···
 {
     "testing": {
-        "version": "6.6-rc7",
-        "hash": "sha256:1zzd32ya4hldfywicgpnc2cyd412s7q9c31qvxx2nl9nkx11xsxv"
+        "version": "6.7-rc1",
+        "hash": "sha256:1a071vvmm08sp48d0arqzcmqnz5xdb1vflfhxcqwmpzaabjrgadk"
     },
     "6.5": {
         "version": "6.5.11",