Spark: Fix failing Spark streaming rate limit unit test (apache#7470)

Co-authored-by: Prashant Singh <psinghvk@amazon.com>

spark/v3.4/spark/src/test/java/org/apache/iceberg/spark/source/TestStructuredStreamingRead3.java

@@ -52,13 +52,15 @@
 import org.apache.spark.sql.Dataset;
 import org.apache.spark.sql.Encoders;
 import org.apache.spark.sql.Row;
+import org.apache.spark.sql.internal.SQLConf;
 import org.apache.spark.sql.streaming.DataStreamWriter;
 import org.apache.spark.sql.streaming.OutputMode;
 import org.apache.spark.sql.streaming.StreamingQuery;
 import org.assertj.core.api.Assertions;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
+import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
@@ -110,6 +112,12 @@ public TestStructuredStreamingRead3(
               Lists.newArrayList(
                   new SimpleRecord(15, "fifteen"), new SimpleRecord(16, "sixteen"))));
 
+  @BeforeClass
+  public static void setupSpark() {
+    // disable AQE as tests assume that writes generate a particular number of files
+    spark.conf().set(SQLConf.ADAPTIVE_EXECUTION_ENABLED().key(), "false");
+  }
+
   @Before
   public void setupTable() {
     sql(