support bundles are owned by root

## What happened?

Support bundles are generated with `root`s UID/GID even when EKS-A is invoked with a non-root user.

```
-rw-r--r-- 1 root root 596744 Mar 10 01:08 support-bundle-2023-03-10T01_08_38.tar.gz
-rw-r--r-- 1 root root 1350058 Mar 10 01:09 support-bundle-2023-03-10T01_08_54.tar.gz
```

## What do you expect?

The bundle is written with the UID/GID of the user invoking EKS-A.

Start by tracing the support-bundle generation entry point and reproduce the behavior while invoking EKS-A as a non-root user. Inspect where the bundle archive is created and verify that the completed bundle's UID/GID match the invoking user; confirm the result with a non-root test or reproduction.

Written by the indexing model from the issue text.