Publish to OpenVSX

[matifali]

To support non-MS VScode versions, like Cursor IDE, that can not access the VSCode marketplace, investigate if we can publish to OpenVSX Registry. Coder depends on Remote Development, which is also exclusively available in VSCode marketplace.

[code-asher]

Supposedly Cursor uses anysphere.open-remote-ssh but that is not available in Open VSX either. I wonder if this one works instead: https://open-vsx.org/extension/jeanp413/open-remote-ssh

Or maybe anysphere.open-remote-ssh is included in the base distribution of Cursor? If so we could just remove the dependency, but then it would not work with VSCodium for example.