Exclue headers in refresh for client credential flow

Author: danielcweeks

core/src/main/java/org/apache/iceberg/rest/auth/OAuth2Util.java

@@ -18,10 +18,6 @@
  */
 package org.apache.iceberg.rest.auth;
 
-import static org.apache.iceberg.TableProperties.COMMIT_MAX_RETRY_WAIT_MS_DEFAULT;
-import static org.apache.iceberg.TableProperties.COMMIT_MIN_RETRY_WAIT_MS_DEFAULT;
-import static org.apache.iceberg.TableProperties.COMMIT_TOTAL_RETRY_TIME_MS_DEFAULT;
-
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.databind.JsonNode;
 import java.io.IOException;
@@ -56,6 +52,10 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import static org.apache.iceberg.TableProperties.COMMIT_MAX_RETRY_WAIT_MS_DEFAULT;
+import static org.apache.iceberg.TableProperties.COMMIT_MIN_RETRY_WAIT_MS_DEFAULT;
+import static org.apache.iceberg.TableProperties.COMMIT_TOTAL_RETRY_TIME_MS_DEFAULT;
+
 public class OAuth2Util {
   private OAuth2Util() {}
 
@@ -186,7 +186,7 @@ private static OAuthTokenResponse refreshToken(
       }
 
       return fetchToken(
-          client, headers, config.credential(), config.scope(), config.oauth2ServerUri());
+          client, Map.of(), config.credential(), config.scope(), config.oauth2ServerUri());
     }
   }