Add justification for changing func signature

Author: whuffman36

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

@@ -2,6 +2,12 @@
 <!-- see http://www.mojohaus.org/clirr-maven-plugin/examples/ignored-differences.html -->
 <differences>
   <!-- TODO: REMOVE AFTER RELEASE -->
+  <difference>
+    <differenceType>7004</differenceType>
+    <className>com/google/cloud/bigquery/BigQueryRetryHelper</className>
+    <method>com.google.cloud.bigquery.V runWithRetries(java.util.concurrent.Callable, com.google.api.gax.retrying.RetrySettings, com.google.api.gax.retrying.ResultRetryAlgorithm, com.google.api.core.ApiClock, com.google.cloud.bigquery.BigQueryRetryConfig, boolean, io.opentelemetry.api.trace.Tracer)</method>
+    <justification>A Tracer object is needed to use Otel and runWithRetries is only called in a few files, so it should be fine to update the signature</justification>
+  </difference>
   <difference>
     <differenceType>7004</differenceType>
     <className>com/google/cloud/bigquery/spi/v2/BigQueryRpc</className>