Publish the VS Code extension to OpenVSX

### Description

A big hello to the NetBeans team 👋!
I would like to kindly ask you to publish this extension to the Open VSX marketplace.

## Context

Unfortunately, as Microsoft prohibits usages of the Microsoft marketplace by any other products or redistribution of `.vsix` files from it, in order to use VS Code extensions in non-Microsoft products, we kindly ask that you take ownership of the VS Code extension namespace in [OpenVSX](https://open-vsx.org/) and publish this extension on Open VSX.

## What is OpenVSX? Why does it exist?

OpenVSX is a vendor neutral alternative to the MS marketplace used by most other derivatives of VS Code like [VSCodium](https://vscodium.com/), [Gitpod](gitpod.io), [OpenVSCode](https://github.com/gitpod-io/openvscode-server), [Theia](https://theia-ide.org/) based IDEs, and others.

## How can you publish to Open VSX?

Me and the team made [a doc](https://github.com/open-vsx/publish-extensions/blob/master/docs/direct_publish_setup.md) describing the whole process. If you already have a pipeline in place for publishing to the Microsoft Marketplace, you can simply have another step after `vsce publish` which would call `npx ovsx publish` (it works in almost the same way).

I found that the build step is defined here, but couldn't find a publishing step.
https://github.com/apache/netbeans/blob/5a7698294c136fac350595022e309348cde817e3/java/java.lsp.server/build.xml#L102-L108

### Are you willing to submit a PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow the Apache Software Foundation's [Code of Conduct](https://www.apache.org/foundation/policies/conduct.html)