As of 5789287a95, esbuild was updated to
0.18.5 which introduced a new transpilation called "Static fields with
assign semantics now use static blocks if possible"
(https://github.com/evanw/esbuild/blob/v0.18.5/CHANGELOG.md). This
causes generation of JavaScript code that is incompatible with KWin's
JavaScript engine, resulting in errors loading Bismuth.
This update uses esbuild's `--target` option to generate compatible
output code.
