tree-wide: drop copyright headers from frequent contributors

Fixes #9320.

for p in Shapovalov Chevalier Rozhkov Sievers Mack Herrmann Schmidt Rudenberg Sahani Landden Andersen Watanabe; do
  git grep -e 'Copyright.*'$p -l|xargs perl -i -0pe 's|/([*][*])?[*]\s+([*#]\s+)?Copyright[^\n]*'$p'[^\n]*\s*[*]([*][*])?/\n*|\n|gms; s|\s+([*#]\s+)?Copyright[^\n]*'$p'[^\n]*\n*|\n|gms'
done

src/basic/bpf-program.h

@@ -2,8 +2,6 @@
 #pragma once
 
 /***
-  Copyright © 2016 Daniel Mack
-
   [Except for the stuff copy/pasted from the kernel sources, see below]
 ***/