This replaces Riot with Element in various CI scripts, modules, parameters, etc. This _should_ be the last major rebranding pass (hopefully). Fixes https://github.com/vector-im/element-web/issues/14894
Because the tests are run directly by node, we have to use the CommonJS module syntax. We could run the thing through babel, but then we just have another babel. Windows instructions are from experience and may not be optimized.