Update to Linux 6.18

[a-gavin]

As before, generate latest Linux 6.18 kernel bindings.

During generation, I noticed the following warnings which I had seen in previous CI runs if I'm not mistaken. My development environment uses clang-19, if it helps.

...
clang diag: modules/general.h:203:9: warning: 'UFFDIO_REGISTER_MODE_MINOR' macro redefined [-Wmacro-redefined]
clang diag: modules/general.h:205:9: warning: 'UFFDIO_COPY_MODE_DONTWAKE' macro redefined [-Wmacro-redefined]
clang diag: modules/general.h:206:9: warning: 'UFFDIO_COPY_MODE_WP' macro redefined [-Wmacro-redefined]
clang diag: modules/general.h:208:9: warning: 'UFFDIO_ZEROPAGE_MODE_DONTWAKE' macro redefined [-Wmacro-redefined]
...
Generating bindings for system on Linux v6.18 architecture x32
clang diag: warning: argument unused during compilation: '-nostdlibinc' [-Wunused-command-line-argument]
Generating bindings for xdp on Linux v6.18 architecture x32
clang diag: warning: argument unused during compilation: '-nostdlibinc' [-Wunused-command-line-argument]
All bindings generated!

Full logs attached here:
build_logs.txt

[sunfishcode]

Looks good! Please don't include the build logs in the PR though. For those macro redefinition warnings, we can just remove the macros from modules/general.h now that they're defined by the Linux headers.