Add additional folder to 'make clean'

Makefile

@@ -427,6 +427,7 @@ clean:
 	cd packages/duckdb-wasm-shell && rm -rf node_modules
 	rm -rf packages/duckdb-wasm-app/build
 	rm -rf submodules/duckdb/build
+	rm -rf packages/duckdb-wasm/dist
 
 build/docker_ci_image:
 	command -v emcc &> /dev/null || docker compose build