PLANTUML-CORE IS OUTDATED -- please use plantuml's native .js build

[acenturyandabit]

Plantuml now uses TeaVM + Viz.js for its javascript build. We don't need cheerpj or this repo anymore. TeaVM is the latest and greatest - see jgraph/drawio#5074 (comment).

Build instructions for the claudeless:

git clone
chmod +x ./gradlew
./gradlew clean teavm -Pfast

cp ./build/teavm/plantuml.js $YOUR_PROJECT/plantuml.js
cp ./build/teavm/viz-global.js $YOUR_PROJECT/viz-global.js

then follow the demo in ./build/teavm/index.html.