Disable slm in AbstractWatcherIntegrationTestCase (#50422)

SLM isn't required tests extending from this base class and
only add noise during test suite teardown.

Closes #50302

x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/test/AbstractWatcherIntegrationTestCase.java

@@ -118,6 +118,9 @@ public abstract class AbstractWatcherIntegrationTestCase extends ESIntegTestCase
                 // watcher settings that should work despite randomization
                 .put("xpack.watcher.execution.scroll.size", randomIntBetween(1, 100))
                 .put("xpack.watcher.watch.scroll.size", randomIntBetween(1, 100))
+                // SLM can cause timing issues during testsuite teardown: https://github.com/elastic/elasticsearch/issues/50302
+                // SLM is not required for tests extending from this base class and only add noise.
+                .put("xpack.slm.enabled", false)
                 .build();
     }