Move AsVector utility to fixture.h

PiperOrigin-RevId: 690577546
Change-Id: I2cebcffa1f2e3b0789f43e772e364c4762719ab3

test/user/user_model_test.cc

@@ -26,7 +26,6 @@
 #include <absl/strings/str_format.h>
 #include <mujoco/mjmodel.h>
 #include <mujoco/mujoco.h>
-#include "src/cc/array_safety.h"
 #include "test/fixture.h"
 
 namespace mujoco {
@@ -44,10 +43,6 @@ static std::vector<mjtNum> GetRow(const mjtNum* array, int ncolumn, int row) {
                              array + ncolumn * (row + 1));
 }
 
-std::vector<mjtNum> AsVector(const mjtNum* array, int n) {
-  return std::vector<mjtNum>(array, array + n);
-}
-
 // ----------------------------- test mjCModel  --------------------------------
 
 using UserCModelTest = MujocoTest;