jool-dkms FTBS with linux 6.2 on jammy

[Impact]

jool-dkms fails to build with linux 6.2 with the following errors:

/var/lib/dkms/jool-dkms/4.1.7/build/src/mod/common/nl/nl_handler.c:211:21: error: initialization of ‘int (*)(const struct genl_split_ops *, struct sk_buff *, struct genl_info *)’ from incompatible pointer type ‘int (*)(const struct genl_ops *, struct sk_buff *, struct genl_info *)’ [-Werror=incompatible-pointer-types]
  211 | .pre_doit = pre_handle_request,
      | ^~~~~~~~~~~~~~~~~~
/var/lib/dkms/jool-dkms/4.1.7/build/src/mod/common/nl/nl_handler.c:211:21: note: (near initialization for ‘jool_family.pre_doit’)
/var/lib/dkms/jool-dkms/4.1.7/build/src/mod/common/nl/nl_handler.c:212:22: error: initialization of ‘void (*)(const struct genl_split_ops *, struct sk_buff *, struct genl_info *)’ from incompatible pointer type ‘void (*)(const struct genl_ops *, struct sk_buff *, struct genl_info *)’ [-Werror=incompatible-pointer-types]
  212 | .post_doit = post_handle_request,
      | ^~~~~~~~~~~~~~~~~~~
/var/lib/dkms/jool-dkms/4.1.7/build/src/mod/common/nl/nl_handler.c:212:22: note: (near initialization for ‘jool_family.post_doit’)

[Test case]

 $ sudo apt install jool-dkms

With the fix applied:

 - release kernel 5.15:

Building for 5.15.0-77-generic
Building initial module for 5.15.0-77-generic
EFI variables are not supported on this system
/sys/firmware/efi/efivars not found, aborting.
Done.

jool_common.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/5.15.0-77-generic/updates/dkms/

 - hwe kernel 6.2:

Building for 6.2.0-25-generic
Building initial module for 6.2.0-25-generic
EFI variables are not supported on this system
/sys/firmware/efi/efivars not found, aborting.
Done.

jool_common.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/6.2.0-25-generic/updates/dkms/

[Fix]

Backport the right patches from lunar to support the new 6.2 kernel ABI.

[Regression potential]

Jool is an IP/ICMP translator, so with this change we may experience networking regressions in those systems that are using this dkms.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: jool-dkms 4.1.7-1
ProcVersionSignature: User Name 6.2.0-23.23~22.04.1-generic 6.2.12
Uname: Linux 6.2.0-23-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: unknown
Date: Sun Jun 11 17:00:15 2023
PackageArchitecture: all
SourcePackage: jool
UpgradeStatus: No upgrade log present (probably fresh install)