Delete buggy detection for Mosel (#1936)

The “Lexer Development” doc says:

    It is important to note that self.detect? should only return true if it is
    100% sure that the language is detected.

The specified function matches any file containing the words “model” or
“package” at the beginning of a line, which misfires quite a lot!

Regularly spotted with debian/changelog files on https://salsa.debian.org/
(powered by GitLab).

Co-authored-by: Cyril Brulebois <kibi@debian.org>

lib/rouge/lexers/mosel.rb

@@ -13,10 +13,6 @@ class Mosel < RegexLexer
 
       mimetypes 'text/x-mosel'
 
-      def self.detect?(text)
-        return true if text =~ /^\s*(model|package)\s+/
-      end
-
       id = /[a-zA-Z_][a-zA-Z0-9_]*/
 
       ############################################################################################################################