Do not pass dynamicHeight as DOM attribute to textarea

[lorumic]

Done

• A tiny change to remove a React warning, complaining that an unrecognised "dynamicHeight" prop was being set on a DOM element:

QA

1. Run the LXD-UI:
   • On the demo server via the link posted by @webteam-app below. This is only available for PRs created by collaborators of the repo. Ask @lorumic or @edlerd for access. The warning seems to appear only when running locally (dev).
   • With a local copy of this branch, run as described here.
2. Perform the following QA steps:
   • Open the browser console from the dev tools
   • Go to a page where there is an auto-expanding textarea, e.g. the instance detail page, configuration tab
   • Check that no warning like the one in the screenshot above appears in the console

[webteam-app]

Demo starting at https://lxd-ui-571.demos.haus

[mas-who]

Thank you for the fix!