collapse_channel.py 1.4: improve script logic and overall stability, with better error handling, add /help text, add SPDX copyright and license tags

Author: flashcode

REUSE.toml

@@ -895,12 +895,6 @@ precedence = "override"
 SPDX-FileCopyrightText = "2013 Isaac Ross <foxxysauce@gmail.com>"
 SPDX-License-Identifier = "GPL-2.0-or-later"
 
-[[annotations]]
-path = "python/collapse_channel.py"
-precedence = "override"
-SPDX-FileCopyrightText = "2019-2024 Nils Görs <weechatter@arcor.de>"
-SPDX-License-Identifier = "GPL-3.0-or-later"
-
 [[annotations]]
 path = "python/completion.py"
 precedence = "override"