Bump kubernetes-maven-plugin from 1.7.0 to 1.8.0

Bumps kubernetes-maven-plugin from 1.7.0 to 1.8.0.

---
updated-dependencies:
- dependency-name: org.eclipse.jkube:kubernetes-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

chapter-2/thorntail-hello/pom.xml

@@ -13,7 +13,7 @@
 
     <properties>
         <version.thorntail>2.7.0.Final</version.thorntail>
-        <version.jkube>1.7.0</version.jkube>
+        <version.jkube>1.8.0</version.jkube>
 
         <maven.compiler.source>11</maven.compiler.source>
         <maven.compiler.target>11</maven.compiler.target>