chore(deps): update appengine packages to v2.0.26

Author: renovate-bot

pom.xml

@@ -459,7 +459,7 @@
       - google-api-java-client/google-api-client-assembly/android-properties (make the filenames match the version here)
       - Internally, update the default features.json file
     -->
-    <project.appengine.version>2.0.6</project.appengine.version>
+    <project.appengine.version>2.0.26</project.appengine.version>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.http.version>1.43.3</project.http.version>
     <project.jsr305.version>3.0.2</project.jsr305.version>