Small tweaks for update-copyright.py

update-copyright.py --this-year FAILs on two spots in the modula2
directories.
One is gpl_v3_without_node.texi, I think that is similar to other
license files which we already exclude from updates.
And the other is GmcOptions.cc, which has lines like
  mcPrintf_printf0 ((const char *) "Copyright ", 10);
  mcPrintf_printf1 ((const char *) "Copyright (C) %d Free Software Foundation, Inc.\\n", 49, (const unsigned char *) &year, (sizeof (year)-1));
  mcPrintf_printf1 ((const char *) "Copyright (C) %d Free Software Foundation, Inc.\\n", 49, (const unsigned char *) &year, (sizeof (year)-1));
which update-copyhright.py obviously can't grok.  The file is generated
and doesn't contain normal Copyright year which should be updated, so I think
it is also ok to skip it.

2024-01-03  Jakub Jelinek  <jakub@redhat.com>

	* update-copyright.py (GenericFilter): Skip gpl_v3_without_node.texi.
	(GCCFilter): Skip GmcOptions.cc.