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/tts/tts.cpp

@@ -10,6 +10,7 @@
 #include <nlohmann/json.hpp>
 
 #include <algorithm>
+#include <clocale>
 #include <cmath>
 #include <cstdio>
 #include <fstream>
@@ -536,6 +537,8 @@ static std::string audio_data_from_speaker(json speaker, const outetts_version t
 }
 
 int main(int argc, char ** argv) {
+    std::setlocale(LC_NUMERIC, "C");
+
     common_params params;
 
     params.out_file = "output.wav";