Implement nightly releases

[ttytm]

Implement nightly releases that are automatically updated when changes to the main branch are made.

This change should work very well as it is, but there are always improvements to make.

E.g. possible future improvements:

• Making releases could be split into it's own release workflow and file. This would require some re-organisation, since artifacts would need to be downloaded to make them accessible for a separate job and the release preparation would need to be done there, after downloading.
• What triggers a nightly release could be narrowed down further to changes that are decided to be relevant (the separate workflow mentioned above would be supplementary for this).

[hassandraga]

Other improvements to add in the future:

• Windows ARM64 (Needed for Qualcomm & Microsoft Surface devices)
• Linux ARM64 (Needed for Raspberry Pi devices)

[ttytm]

We can probably update the link for the latest beta build to https://github.com/webui-dev/webui/releases/tag/nightly

[hassandraga]

We thought about it at the same moment! https://github.com/webui-dev/webui/commit/c50a576b906e2e83b083635b233d5ac6f9cb2668