build: skip showcase deploy (googleapis#12929)

We added java-showcase to the top-level folders and automation ensures
it is part of the reactor. This setting ensures that we don't try to
deploy the java-showcase packages.

Author: chingor13

java-showcase/pom.xml

@@ -24,6 +24,8 @@
     <checkstyle.skip>true</checkstyle.skip>
     <clirr.skip>true</clirr.skip>
     <enforcer.skip>true</enforcer.skip>
+    <maven.deploy.skip>true</maven.deploy.skip>
+    <skipNexusStagingDeployMojo>true</skipNexusStagingDeployMojo>
     <mdep.analyze.skip>true</mdep.analyze.skip><!-- The showcase modules are not meant for library customers. -->
   </properties>
 

sdk-platform-java/hermetic_build/library_generation/utils/pom_generator.py

@@ -71,6 +71,7 @@ def get_version_from(
     [
         "google-auth-library-java",
         "sdk-platform-java",
+        "java-showcase",
     ]
 )