Retract lexical cookie source load warning

Retract lexical cookie source load warning

On balance it seems likely that the warning would annoy more people than
it would help, so let them deal with any actual problems when the
default is changed instead.  See discussion at:
https://lists.gnu.org/archive/html/emacs-devel/2024-05/msg00250.html

* src/lread.c (string_suffix_p, warn_missing_cookie, Fload)
(Feval_buffer):
* lisp/international/mule.el (load-with-code-conversion):
* lisp/startup.el (command-line--load-script):
* etc/NEWS:
Revert all changes, except for the generalised
`lisp_file_lexical_cookie` which may prove useful in the future.