Continuously getting error in log when creating new content item with tag

Steps to reproduce

1.  Configure content tagging for a new workspace follow our documentation in How to enable content tags for a content app
2.  Register it as taggable workspace
3. Create a new item and save it.
4. Check the log to find the error javax.jcr.PathNotFoundException: /untitled/mgnl:tags and also WARN org.apache.jackrabbit.core.SessionImpl : Unclosed session detected...

.. Logs, screenshots, gifs...

Expected results

• Do not process the case of newly created node so that the error and warning should not happen.

.. Justify non-trivial expectations with a link to a doc or a relevant discussion.

Actual results

• Logs may flood the console and producing high load to server logging system.

Workaround

• N/A

Development notes

• Please note that not always a newly created node named "untitled", sometimes it is "untitled0|1|2".
• Error definitely happen at info.magnolia.contenttags.TagsModule.lambda$null$1(TagsModule.java:139) within the observation.
• Would be better if we can re-architect the mechanism to get rid of such observation on creating node, but after saving node when we have the content node created successfully already.
• Reference to attached error log for an example. Also usecase verified from related ticket.