feat: Fix dropreason for Linux 6.10+

[invidian]

Description

This PR updates vmlinux.h to include struct proto_accept_arg from Linux 6.10+ (https://github.com/torvalds/linux/commit/92ef0fd55ac80dfc2e4654edfe5d1ddfa6e070fe) and then makes use of it in dropreason plugin to make plugin compatible with both kernels 6.10+ and older using bpf_core_type_exists.

Related Issue

#1906

Checklist

• [x] I have read the contributing documentation.
• [x] I signed and signed-off the commits (git commit -S -s ...). See this documentation on signing commits.
• [x] I have correctly attributed the author(s) of the code.
• [x] I have tested the changes locally.
• [x] I have followed the project's style guidelines.
• [x] I have updated the documentation, if necessary.
• [x] I have added tests, if applicable.

Additional Notes

~vmlinux.h still needs to be regenerated for arm64 which I'll try to soon.~ Done.

Also, I need to test those changes back on kernel 6.6 to make sure it's still working

Also, I am not aware if this change is covered by unit tests which would detect the regressions.

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[invidian]

Thanks for reviewing. I removed binary files from the PR. At the moment vmlinux.h files are taken from https://github.com/inspektor-gadget/inspektor-gadget/tree/main/include/gadget, just to make images to build. Appropriate sourcing is definitely worth it. It shouldn't have any custom changes though.