Remove name attribute from most plugin tags in dm_control.

Fixes #450.

PiperOrigin-RevId: 670217358
Change-Id: Ia6bec45391951bfeddd05f0cf00c16ceb0205943

Author: nimrod-gileadi

dm_control/mjcf/schema.xml

@@ -983,7 +983,6 @@
           <children>
             <element name="plugin" repeated="true" namespace="mesh">
               <attributes>
-                <attribute name="name" type="string"/>
                 <attribute name="plugin" type="string"/>
                 <attribute name="instance" type="reference" reference_namespace="plugin"/>
               </attributes>
@@ -1079,7 +1078,6 @@
           <children>
             <element name="plugin" repeated="true" namespace="geom">
               <attributes>
-                <attribute name="name" type="string"/>
                 <attribute name="plugin" type="string"/>
                 <attribute name="instance" type="reference" reference_namespace="plugin"/>
               </attributes>
@@ -1184,7 +1182,6 @@
           <children>
             <element name="plugin" repeated="true" namespace="flexcomp">
               <attributes>
-                <attribute name="name" type="string"/>
                 <attribute name="plugin" type="string"/>
                 <attribute name="instance" type="reference" reference_namespace="plugin"/>
               </attributes>
@@ -1252,7 +1249,6 @@
           <children>
             <element name="plugin" repeated="true" namespace="composite">
               <attributes>
-                <attribute name="name" type="string"/>
                 <attribute name="plugin" type="string"/>
                 <attribute name="instance" type="reference" reference_namespace="plugin"/>
               </attributes>
@@ -1370,7 +1366,6 @@
           <children>
             <element name="plugin" repeated="true" namespace="body">
               <attributes>
-                <attribute name="name" type="string"/>
                 <attribute name="plugin" type="string"/>
                 <attribute name="instance" type="reference" reference_namespace="plugin"/>
               </attributes>
@@ -1468,7 +1463,6 @@
               <children>
                 <element name="plugin" repeated="true" namespace="geom">
                   <attributes>
-                    <attribute name="name" type="string"/>
                     <attribute name="plugin" type="string"/>
                     <attribute name="instance" type="reference" reference_namespace="plugin"/>
                   </attributes>
@@ -1573,7 +1567,6 @@
               <children>
                 <element name="plugin" repeated="true" namespace="flexcomp">
                   <attributes>
-                    <attribute name="name" type="string"/>
                     <attribute name="plugin" type="string"/>
                     <attribute name="instance" type="reference" reference_namespace="plugin"/>
                   </attributes>
@@ -1641,7 +1634,6 @@
               <children>
                 <element name="plugin" repeated="true" namespace="composite">
                   <attributes>
-                    <attribute name="name" type="string"/>
                     <attribute name="plugin" type="string"/>
                     <attribute name="instance" type="reference" reference_namespace="plugin"/>
                   </attributes>