[FIX] Remove __cpp_nontype_template_parameter_class

The correct version would have been __cpp_nontype_template_args >= 201911L. All supported compilers fulfil this.

include/seqan3/io/sam_file/sam_tag_dictionary.hpp

@@ -70,22 +70,9 @@ inline namespace literals
  * The purpose of those tags is to fill or query the seqan3::sam_tag_dictionary for a specific key (tag_id) and
  * retrieve the corresponding value.
  */
-
-#ifdef __cpp_nontype_template_parameter_class
 template <small_string<2> str> // TODO: better handling if too large string is provided?
 constexpr uint16_t operator""_tag()
 {
-#else // GCC/Clang extension
-#    pragma GCC diagnostic push
-#    pragma GCC diagnostic ignored "-Wpedantic"
-template <typename char_t, char_t... s>
-constexpr uint16_t operator""_tag()
-{
-    static_assert(std::same_as<char_t, char>, "Illegal SAM tag: Type must be char.");
-    constexpr small_string<sizeof...(s)> str{std::array<char, sizeof...(s)>{s...}};
-#    pragma GCC diagnostic pop
-#endif
-
     static_assert(str.size() == 2, "Illegal SAM tag: Exactly two characters must be given.");
 
     constexpr char char0 = str[0];