Fix random in TestBinariesObject.testDeleteOrphanedBinaries Postgres

[2022-04-08T08:57:18.745Z] [ERROR] Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 8.384 s <<< FAILURE! - in org.nuxeo.ecm.restapi.server.jaxrs.management.TestBinariesObject

[2022-04-08T08:57:18.745Z] [ERROR] testDeleteOrphanedBinaries(org.nuxeo.ecm.restapi.server.jaxrs.management.TestBinariesObject)  Time elapsed: 2.731 s  <<< FAILURE!

[2022-04-08T08:57:18.745Z] java.lang.AssertionError: expected:<4> but was:<0>

[2022-04-08T08:57:18.745Z] 	at org.junit.Assert.fail(Assert.java:89)

[2022-04-08T08:57:18.745Z] 	at org.junit.Assert.failNotEquals(Assert.java:835)

[2022-04-08T08:57:18.745Z] 	at org.junit.Assert.assertEquals(Assert.java:647)

[2022-04-08T08:57:18.745Z] 	at org.junit.Assert.assertEquals(Assert.java:633)

[2022-04-08T08:57:18.745Z] 	at org.nuxeo.ecm.restapi.server.jaxrs.management.TestBinariesObject.garbageCollectBinariesAndAssert(TestBinariesObject.java:117)

[2022-04-08T08:57:18.745Z] 	at org.nuxeo.ecm.restapi.server.jaxrs.management.TestBinariesObject.testDeleteOrphanedBinaries(TestBinariesObject.java:92)