JetBrains: We shouldn't need Java to install the plugin

Created by: vdavid

As @ryankscott reported: if you don't have Java installed (e.g. if you use WebStorm), you get this when installing the plugin:

It’s because we have <depends>com.intellij.java</depends> in plugin.xml, added by @philipp-spiess on 2022-06-07. It’s for getting the syntax theme in ThemeUtil.java. At the end of the day, we can work with any language, but it’ll be a bit tricky because the syntax theme structure is different for each language.