[Functions] Function workers require more memory on Pulsar 2.8.x+

**Describe the bug**
Function workers consume more resident RAM memory on Pulsar 2.8.x compared to Pulsar 2.7.x .
The "built-in" NAR files from the connectors directory are loaded and retained in memory as NARClassLoaders.
This change was made as part of #9413.
This could lead to OOM killer killing the function worker on Kubernetes when there are low limits for the function worker. ​

**Expected behavior**
The expectation is that a function worker on Pulsar 2.8.x+ wouldn't require more memory that Pulsar 2.7.x .

The issue names no files or tests; start by tracing how built-in NAR files from the connectors directory are loaded and retained as NARClassLoaders in the function worker. Compare memory behavior between Pulsar 2.7.x and 2.8.x+, then verify that the worker no longer requires increased resident RAM under the reported Kubernetes limits.

Written by the indexing model from the issue text.