GEODE-6063 remove PublishArtifacts from Geode release pipelines

[onichols-pivotal]

This PR will resolve the red job on the release/1.8.0 pipeline. Releases should only be signed and published manually, so unlike develop branch which publishes a snapshot automatically after every successful build, release pipelines do not need publish step at all.

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[galen-pivotal]

So we will only not PublishArtifacts if we are on apache on a branch that is not develop. Seems reasonable enough to assume that's a release branch. Do we ever build with a repo that is not apache?

[metatype]

Maybe on a fork?

[jake-at-work]

Downstream consumers of the pipeline may publish their releases without the manual process Apache Geode goes through.

[nonbinaryprogrammer]

IntegrationTestOpenJDK11 failed with known flaky test with stacktrace:
org.apache.geode.distributed.ServerLauncherRemoteFileIntegrationTest > startDeletesStaleControlFiles FAILED java.lang.IllegalStateException: Status file '/tmp/junit2902603449106298011/vf.gf.server.status' is blank

DistributedTestOpenJDK8 failed with known flaky test GEODE-5655 with stacktrace:
org.apache.geode.session.tests.Jetty9ClientServerTest > containersShouldShareDataRemovals FAILED org.codehaus.cargo.container.ContainerException: Failed to stop the Jetty 9.4.12.v20180830 container. Check the [/home/geode/geode/geode-assembly/build/distributedTest133/cargo_logs/JETTY9_client-server_containersShouldShareDataRemovals_0_1136207203814/container.log] file containing the container logs for more details. Caused by: org.codehaus.cargo.container.ContainerException: Server port 21900 did not shutdown within the timeout period [120000]