[ci][hotfix] Enable parallel execution for pipeline-e2e tests

Change forkCount from 1 to 2 to enable parallel test execution.
This should reduce the total test time from ~80 minutes to ~40-50 minutes.

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

Author: yuxiqian

flink-cdc-e2e-tests/flink-cdc-pipeline-e2e-tests/pom.xml

@@ -444,7 +444,8 @@ limitations under the License.
                             <excludes>
                                 <exclude>**/MysqlE2eWithYarnApplicationITCase.java</exclude>
                             </excludes>
-                            <forkCount>1</forkCount>
+                            <!-- Use fixed parallelism of 2 for e2e tests -->
+                            <forkCount>2</forkCount>
                             <systemPropertyVariables>
                                 <moduleDir>${project.basedir}</moduleDir>
                             </systemPropertyVariables>