[chore] Update js process runtime implementation notes

[thompson-tomo]

Fixes #1443

Changes

This switches the value of user agent to be the description attribute just like the other runtimes.

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[github-actions[bot]]

This PR was marked stale due to lack of activity. It will be closed in 7 days.

[thompson-tomo]

Note, the process.runtime entity uses version as an identifying attribute and having ua as the version results in a high cardinality entity.

[trask]

Closing as there does not appear to be engagement from the necessary folks in order to move this forward at this time.