Update render-all.yml to use Node.js 20

[stephaniemyan]

Trying to fix errors in Render all output courses step of Github actions so that it uses Node.js 20, based on these errors while rendering:

Load user automation choices
Node.js 16 actions are deprecated. Please update the following actions to use Node.js 20: actions/checkout@v3, doughepi/yaml-env-action@v1.0.0. For more information see: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/.Show less
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Render bookdown
Node.js 16 actions are deprecated. Please update the following actions to use Node.js 20: actions/checkout@v3. For more information see: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/.

[github-actions[bot]]

:warning: Check: spelling errors did not fully run! Go to the Actions tab to find more info. Post issue to https://github.com/jhudsl/OTTR_Template/issues if this seems incorrect. Comment updated at 2024-02-21 with changes from 88682ab77b6655b0adb8e710dca2f6738fb6614c

[github-actions[bot]]

No broken urls! :tada: Comment updated at 2024-02-21 with changes from 5630431027b5b0ec883daf3e7aa32351082c44fe

[github-actions[bot]]

Re-rendered previews from the latest commit:

• See preview of Bookdown here
• See preview of Coursera/Leanpub version here
• Download the preview of .docx file

Updated at 2024-02-21 with changes from 5630431027b5b0ec883daf3e7aa32351082c44fe