MT#62899 Update copyright holder and license from Artistic + GPL-1+ to GPL-3+

In commit ddd3277692 we replaced the
previous code using the imported Perl code from Jozef Kutej, to
an implementation based on the goss tool.

The Artistic + GPL-1+ license was due to the imported code, but that is
no longer applicable, so we can safely remove the copyright statement
for Jozef Kutej and switch the license to match what other GPL projects
in NGCP use.

Change-Id: Ia8ac16993b03758a9f23b5021e4236c9a32e5df0

debian/copyright

@@ -6,22 +6,22 @@ Upstream-Contact: Michael Prokop <mprokop@sipwise.com>
 Files:
  *
 Copyright:
- Jozef Kutej <jozef@kutej.net>
  2013-2025 Sipwise GmbH, Austria
-License: Artistic or GPL-1+
+License: GPL-3+
 
-License: Artistic
- This program is free software; you can redistribute it and/or modify
- it under the terms of the Artistic License, which comes with Perl.
-Comment:
- On Debian systems, the complete text of the Artistic License can be
- found in '/usr/share/common-licenses/Artistic'.
-
-License: GPL-1+
- This program is free software; you can redistribute it and/or modify
+License: GPL-3+
+ This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 1, or (at your option)
- any later version.
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+ .
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+ .
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 Comment:
- On Debian systems, the complete text of version 1 of the GNU General
- Public License can be found in '/usr/share/common-licenses/GPL-1'.
+ On Debian systems, the full text of the GNU General Public License
+ version 3 can be found in the file '/usr/share/common-licenses/GPL-3'.