tests : avoid building get-model.cpp many times (#26317)

* tests : remove get-model.cpp

* tests : fix quant type selection

tests/test-model-load-cancel.cpp

@@ -1,10 +1,10 @@
 #include "llama.h"
-#include "get-model.h"
+#include "common.h"
 
 #include <cstdlib>
 
 int main(int argc, char *argv[] ) {
-    auto * model_path = get_model_or_exit(argc, argv);
+    auto * model_path = common_get_model_or_exit(argc, argv);
     auto * file = fopen(model_path, "r");
     if (file == nullptr) {
         fprintf(stderr, "no model at '%s' found\n", model_path);