Current build doesn't include language server with binaries

New version (1.29.0) of redhat.java extension should be built in devspaces-vscode-extensions repository.

Current version that is used in DS could be found in openvsx-synch.json

The table that compares extensions in devspaces and devspaces-vscode-extensions repositories: https://docs.google.com/spreadsheets/d/14jwjBJRYRNmSz5tY6CW1s0TvC8mVL4kbMwTiKmOHTiI/edit?usp=sharing