Keep fluent slugs in alphabetical order

Author: francorbacho

compiler/rustc_builtin_macros/messages.ftl

@@ -137,8 +137,6 @@ builtin_macros_format_positional_after_named = positional arguments cannot follo
     .label = positional arguments must be before named arguments
     .named_args = named argument
 
-builtin_macros_format_remove_raw_ident = remove the `r#`
-
 builtin_macros_format_redundant_args = redundant {$n ->
     [one] argument
     *[more] arguments
@@ -153,6 +151,8 @@ builtin_macros_format_redundant_args = redundant {$n ->
     }
     .suggestion = this can be removed
 
+builtin_macros_format_remove_raw_ident = remove the `r#`
+
 builtin_macros_format_requires_string = requires at least a format string argument
 
 builtin_macros_format_string_invalid = invalid format string: {$desc}