Don't require a signing key to publish docs (#8368)

Author: swankjesse

test_docs.sh

@@ -9,7 +9,7 @@
 set -ex
 
 # Test generating the javadoc jars
-./gradlew publishToMavenLocal
+./gradlew publishToMavenLocal -DRELEASE_SIGNING_ENABLED=false
 
 # Generate the API docs
 ./gradlew dokkaHtmlMultiModule