ci(renovate): Only allow digit-versions of the Jira REST client

Do not upgrade to intermediate versions like "5.2.8-platform7-12284590",
see e.g. [1].

[1]: #8831

Signed-off-by: Sebastian Schuberth <sebastian@doubleopen.org>

renovate.json

@@ -18,6 +18,13 @@
   ],
   "labels": ["dependencies"],
   "packageRules": [
+    {
+      "matchPackageNames": [
+        "com.atlassian.jira:jira-rest-java-client-api",
+        "com.atlassian.jira:jira-rest-java-client-app"
+      ],
+      "allowedVersions": "/^[0-9]+\\.[0-9]+\\.[0-9]+$/"
+    },
     {
       "matchPackageNames": [
         "org.springframework:spring-core"