Switch to renovate for dependency management (#603)

* Switch to renovate

* Remove obsolete comment

Author: NotMyFault

.github/dependabot.yml

@@ -0,0 +1,24 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": [
+    "config:base",
+    ":semanticCommitsDisabled",
+    "schedule:earlyMondays"
+  ],
+  "automerge": true,
+  "reviewers": [
+    "team:core"
+  ],
+  "regexManagers": [
+    {
+      "fileMatch": ["common-files/.mvn/extensions.xml"],
+      "matchStrings": ["<version>(?<currentValue>.*?)<\/version>"],
+      "depNameTemplate": "io.jenkins.tools.incrementals:git-changelist-maven-extension",
+      "datasourceTemplate": "maven"
+    }
+  ],
+  "labels": [
+    "dependencies"
+  ],
+  "rebaseWhen": "conflicted"
+}

.github/renovate.json

@@ -47,7 +47,6 @@
         <module>empty-plugin</module>
         <module>hello-world</module>
         <module>global-configuration</module>
-        <!-- if adding new archetypes please also update .github/dependabot.yml -->
     </modules>
     <scm child.scm.connection.inherit.append.path="false" child.scm.developerConnection.inherit.append.path="false" child.scm.url.inherit.append.path="false">
         <connection>scm:git:[email protected]/jenkinsci/archetypes.git</connection>