Remove support for CR as a line ending

Author: stasm

spec/fluent.ebnf

@@ -98,7 +98,6 @@ digit               ::= [0-9]
 inline_space        ::= ("\u0020" | "\u0009")+
 line_end            ::= "\u000D\u000A"
                       | "\u000A"
-                      | "\u000D"
                       | EOF
 blank_line          ::= inline_space? line_end
 break_indent        ::= line_end blank_line* inline_space

syntax/grammar.mjs

@@ -467,7 +467,6 @@ let line_end =
     either(
         string("\u000D\u000A"),
         string("\u000A"),
-        string("\u000D"),
         eof());
 
 let blank_line =