Enable float32 testing for most MuJoCo engine and user tests.

PiperOrigin-RevId: 886697701
Change-Id: I4a96fae03ea18494c3fcef8eb17b3b6f0863e9b7

test/xml/xml_native_writer_test.cc

@@ -746,6 +746,9 @@ TEST_F(XMLWriterTest, WritesActuatorDefaults) {
 }
 
 TEST_F(XMLWriterTest, WritesFrameDefaults) {
+#ifdef mjUSESINGLE
+  GTEST_SKIP() << "Quat values differ in float32 (euler->quat rounding)";
+#endif
   static constexpr char xml[] = R"(
   <mujoco model="test">
     <default>
@@ -1184,6 +1187,9 @@ TEST_F(XMLWriterTest, ActdimDefaults) {
 }
 
 TEST_F(XMLWriterTest, TrimsDefaults) {
+#ifdef mjUSESINGLE
+  GTEST_SKIP() << "float(0.9) != double(0.9), so default-trimming fails";
+#endif
   static constexpr char xml[] = R"(
   <mujoco>
     <worldbody>