Follow-up to https://github.com/godotengine/build-containers/pull/128.
Also reverts #88 since these new images include JDK 17, and the closure
compiler issue was fixed upstream.
And removes the manual install of gettext which is now also part of the
images.
X11 libs should not be needed to generate the Mono glue anymore (they've been
unnecessary for a while already).
This enables compiling the PO files to smaller binary MO files,
reducing the size of the editor binary which embeds them.
gettext will be added to the base container but I haven't done it
yet, so for now adding it manually here.
