Update the MuJoCo version number ahead of the 3.2.0 release.

PiperOrigin-RevId: 652578624
Change-Id: I8ed6f66ff1247ff7421e3ed0521cf15e1c0b6c79

unity/Editor/Bindings/MujocoBinaryRetriever.cs

@@ -37,7 +37,7 @@ public class MujocoBinaryRetriever {
           if (AssetDatabase.LoadMainAssetAtPath(mujocoPath + "/mujoco.dylib") == null) {
             File.Copy(
                 "/Applications/MuJoCo.app/Contents/Frameworks" +
-                "/mujoco.framework/Versions/Current/libmujoco.3.1.7.dylib",
+                "/mujoco.framework/Versions/Current/libmujoco.3.2.0.dylib",
                 mujocoPath + "/mujoco.dylib");
             AssetDatabase.Refresh();
           }
@@ -45,7 +45,7 @@ public class MujocoBinaryRetriever {
           if (AssetDatabase.LoadMainAssetAtPath(mujocoPath + "/libmujoco.so") == null) {
             File.Copy(
                 Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) +
-                "/.mujoco/mujoco-3.1.7/lib/libmujoco.so.3.1.7",
+                "/.mujoco/mujoco-3.2.0/lib/libmujoco.so.3.2.0",
                 mujocoPath + "/libmujoco.so");
             AssetDatabase.Refresh();
           }