Remove @UpdateForV9 from MetadataMapperTestCase (elastic#113083)

I have reviewed the action taken as part of incrementing the major version to 9. The update to the test is correct, we can remove the annotation. Indices created before 8.6 silently ignore the params, I renamed the test method to clarify that.

test/framework/src/main/java/org/elasticsearch/index/mapper/MetadataMapperTestCase.java

@@ -11,7 +11,6 @@
 
 import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.core.CheckedConsumer;
-import org.elasticsearch.core.UpdateForV9;
 import org.elasticsearch.index.IndexVersion;
 import org.elasticsearch.index.IndexVersions;
 import org.elasticsearch.index.mapper.MapperService.MergeReason;
@@ -144,10 +143,7 @@ public final void testFixedMetaFieldsAreNotConfigurable() throws IOException {
         assertEquals("Failed to parse mapping: " + fieldName() + " is not configurable", exception.getMessage());
     }
 
-    @UpdateForV9
-    // This was previously testing for index versions between 7.0.0 and 8.6.0 but has been bumped to 8.0.0 - 8.6.0
-    // Verify this is the correct action.
-    public void testTypeAndFriendsAreAcceptedBefore_8_6_0() throws IOException {
+    public void testTypeAndFriendsAreSilentlyIgnoredBefore_8_6_0() throws IOException {
         assumeTrue("Metadata field " + fieldName() + " isn't configurable", isConfigurable());
         IndexVersion previousVersion = IndexVersionUtils.getPreviousVersion(IndexVersions.V_8_6_0);
         IndexVersion version = IndexVersionUtils.randomVersionBetween(random(), IndexVersions.MINIMUM_COMPATIBLE, previousVersion);