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>

examples/eval-callback/eval-callback.cpp

@@ -4,6 +4,8 @@
 #include "log.h"
 #include "llama.h"
 #include "llama-cpp.h"
+
+#include <clocale>
 #include <string>
 #include <vector>
 
@@ -29,6 +31,8 @@ static bool run(llama_context * ctx, const common_params & params) {
 }
 
 int main(int argc, char ** argv) {
+    std::setlocale(LC_NUMERIC, "C");
+
     base_callback_data cb_data;
 
     common_params params;