Fix locale-dependent float printing in GGUF metadata (#17331)

* Set C locale for consistent float formatting across all binaries.

* Add C locale setting to all tools binaries

Add std::setlocale(LC_NUMERIC, "C") to all 16 binaries in the tools/
directory to ensure consistent floating-point formatting.

* Apply suggestion from @JohannesGaessler

---------

Co-authored-by: Johannes Gäßler <johannesg@5d6.de>

tools/mtmd/mtmd-cli.cpp

@@ -274,6 +274,8 @@ static int eval_message(mtmd_cli_context & ctx, common_chat_msg & msg) {
 }
 
 int main(int argc, char ** argv) {
+    std::setlocale(LC_NUMERIC, "C");
+
     ggml_time_init();
 
     common_params params;