Remove the problematic license

The code was replaced with new implementation:

https://github.com/ruby/json/pull/567

However, there are still new uncertainties about licenses:

https://github.com/ruby/json/issues/723

ruby.spec

@@ -187,12 +187,6 @@ Release: 18%{?dist}
 # GPL-1.0-or-later OR Artistic-1.0-Perl: win32/win32.c, include/ruby/win32.h,
 #   ext/win32ole/win32ole.c
 #
-# !!! Problematic licenses:
-# LicenseRef-scancode-unicode-mappings: ext/json/generator/generator.c
-#   https://bugs.ruby-lang.org/issues/11844#note-19
-#   https://github.com/flori/json/issues/277
-#   https://github.com/flori/json/pull/567
-#
 # Licenses under review:
 #   .bundle/gems/net-imap-0.4.9/LICENSE.txt
 #   https://gitlab.com/fedora/legal/fedora-license-data/-/issues/506
@@ -537,8 +531,7 @@ provide higher layer features, such like curses and readline.
 %package -n rubygem-json
 Summary:    This is a JSON implementation as a Ruby extension in C
 Version:    %{json_version}
-# Unicode-DFS-2015: ext/json/ext/generator/generator.c
-License:    (Ruby OR BSD-2-Clause) AND Unicode-DFS-2015
+License:    Ruby OR BSD-2-Clause
 Provides:   bundled(rubygem-json) = %{json_version}
 
 %description -n rubygem-json