Cannot publish to OpenVSX due to out of date NodeJS

[datho7561]

When attempting to publish to Open VSX via GitHub Actions:

Run ovsx publish -p ***  --packagePath vscode-microprofile/vscode-microprofile-*-${GITHUB_RUN_NUMBER}.vsix
ovsx requires at least NodeJS version 20. Check your installed version with `node --version`.
Error: Process completed with exit code 1.

We should upgrade the version of node used in the CD pipeline, since node 18 is no longer supported.