build(test): add AXONFLOW_TELEMETRY=off to maven-failsafe environmentVariables

Caught a real telemetry leak: surefire (unit tests) had the migrated
env block, but failsafe (integration tests) had no environmentVariables
block at all. Any `mvn verify` run that exercised an integration test
which constructed an AxonFlow client without overriding
AXONFLOW_CHECKPOINT_URL would have fired a real ping to
checkpoint.getaxonflow.com.

Mirrors the surefire env block. Now both unit and integration test
phases suppress telemetry consistently.

Author: saurabhjain1592

pom.xml

@@ -216,6 +216,9 @@
                         <include>**/*IT.java</include>
                         <include>**/*IntegrationTest.java</include>
                     </includes>
+                    <environmentVariables>
+                        <AXONFLOW_TELEMETRY>off</AXONFLOW_TELEMETRY>
+                    </environmentVariables>
                 </configuration>
             </plugin>