Open warnings

[Ttibsi]

/home/admin/workspace/iris/build/_deps/rawterm-src/rawterm/text.cpp:63:49: warning: implicit conversion changes signedness: 'std::size_t' (aka 'unsigned long') to 'difference_type' (aka 'long') [-Wsign-conver
sion]
   63 |             if (std::regex_search(str.begin() + pos, str.end(), match, ansi_escape_code) &&
      |                                               ~ ^~~
/home/admin/workspace/iris/build/_deps/rawterm-src/rawterm/text.cpp:66:30: warning: implicit conversion changes signedness: 'difference_type' (aka 'long') to 'std::size_t' (aka 'unsigned long') [-Wsign-conver
sion]
   66 |                 pos += match.length();
      |                     ~~ ~~~~~~^~~~~~~~
2 warnings generated.

C++23, clang 19,1.7