fix: exclude all samples from Maven Central publishing

Replaces the skipPublishing property on the Kotlin sample with an
excludeArtifacts list on central-publishing-maven-plugin, so the
exclusion lives next to the publishing configuration, and extends it to
every sample module: they are demos and end-to-end tests, not artifacts
to depend on.

Author: csviri

pom.xml

@@ -642,6 +642,20 @@
               <tokenAuth>true</tokenAuth>
               <autoPublish>true</autoPublish>
               <waitUntil>published</waitUntil>
+              <!-- The samples are demos and end-to-end tests, not artifacts to depend on, so they
+                   are not published. The Kotlin one could not be published anyway: it has no Java
+                   sources, so no javadoc jar is attached to it and Central rejects the whole
+                   deployment with "Javadocs must be provided but not found in entries". -->
+              <excludeArtifacts>
+                <excludeArtifact>sample-operators</excludeArtifact>
+                <excludeArtifact>sample-controller-namespace-deletion</excludeArtifact>
+                <excludeArtifact>sample-kotlin-operator</excludeArtifact>
+                <excludeArtifact>sample-leader-election</excludeArtifact>
+                <excludeArtifact>sample-mysql-schema-operator</excludeArtifact>
+                <excludeArtifact>sample-operations</excludeArtifact>
+                <excludeArtifact>sample-tomcat-operator</excludeArtifact>
+                <excludeArtifact>sample-webpage-operator</excludeArtifact>
+              </excludeArtifacts>
             </configuration>
           </plugin>
         </plugins>

sample-operators/kotlin-operator/pom.xml

@@ -34,7 +34,6 @@
 
   <properties>
     <kotlin.version>2.4.10</kotlin.version>
-    <skipPublishing>true</skipPublishing>
   </properties>
 
   <dependencyManagement>