temporarily disable a jldoctest

(see #2341)

src/Groups/group_characters.jl

@@ -377,7 +377,7 @@ Return an array of strings that contains all those names of character tables
 in the character table library that satisfy the conditions in the array `L`.
 
 # Examples
-```jldoctest
+```
 julia> spor_names = all_character_table_names(is_sporadic_simple => true,
          is_duplicate_table => false);