misc: Add new clirr ignored rule (#2677)

Change-Id: Icae25650f2f44f9ebb803da98b587074f91fbaba

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Fixes #<issue_number_goes_here> ☕️

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Author: trollyxia

google-cloud-bigtable/clirr-ignored-differences.xml

@@ -349,6 +349,26 @@
         <className>com/google/cloud/bigtable/data/v2/models/sql/SqlType</className>
         <method>*protoOf(*)</method>
     </difference>
+    <difference>
+        <differenceType>7004</differenceType>
+        <className>com/google/cloud/bigtable/common/Type$SchemalessProto</className>
+        <method>*</method>
+    </difference>
+    <difference>
+        <differenceType>7004</differenceType>
+        <className>com/google/cloud/bigtable/common/Type$SchemalessEnum</className>
+        <method>*</method>
+    </difference>
+    <difference>
+        <differenceType>7013</differenceType>
+        <className>com/google/cloud/bigtable/common/Type$SchemalessProto</className>
+        <method>*</method>
+    </difference>
+    <difference>
+        <differenceType>7013</differenceType>
+        <className>com/google/cloud/bigtable/common/Type$SchemalessEnum</className>
+        <method>*</method>
+    </difference>
     <difference>
         <!-- BetaApi was added -->
         <differenceType>7012</differenceType>