Move AsVector utility to fixture.h

PiperOrigin-RevId: 690577546
Change-Id: I2cebcffa1f2e3b0789f43e772e364c4762719ab3

test/user/user_objects_test.cc

@@ -20,7 +20,6 @@
 #include <cstring>
 #include <memory>
 #include <string>
-#include <vector>
 
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
@@ -34,10 +33,6 @@ namespace {
 
 constexpr double kInertiaTol = 1e-6;
 
-std::vector<mjtNum> AsVector(const mjtNum* array, int n) {
-  return std::vector<mjtNum>(array, array + n);
-}
-
 using std::string;
 using ::testing::DoubleNear;
 using ::testing::ElementsAre;
@@ -2402,7 +2397,8 @@ TEST_F(UserObjectsTest, BadWeld) {
   int len = 4;
 
   // good model using body semantic
-  string xml = base.replace(pos, len, "<weld body1='1' anchor='0 0 1' torquescale='2'/>");
+  string xml = base.replace(pos, len,
+                            "<weld body1='1' anchor='0 0 1' torquescale='2'/>");
   char error[1024];
   mjModel* m = LoadModelFromString(xml.c_str(), error, sizeof(error));
   ASSERT_THAT(m, NotNull()) << error;