Clear directories when constructing dist (#2205)

Fixes #2198



## Checklist

- [-] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [-] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [-] I have not broken the cheatsheet

Author: pokey

packages/cursorless-vscode/src/scripts/populateDist/populateDist.ts

@@ -1,6 +1,6 @@
 // Copies files into `dist` directory for packaging
 import { copy, exists } from "fs-extra";
-import { lstat, mkdir, readFile, writeFile } from "fs/promises";
+import { lstat, mkdir, readFile, rm, writeFile } from "fs/promises";
 import * as path from "path";
 import { assets } from "./assets";
 import { Context } from "./context";
@@ -75,6 +75,7 @@ export async function run() {
         console.log(`Copying ${fullSource} to ${fullDestination}`);
         // If directory, copy recursively
         if ((await lstat(fullSource)).isDirectory()) {
+          await rm(fullDestination, { recursive: true, force: true });
           await mkdir(fullDestination, { recursive: true });
         }
         await copy(fullSource, fullDestination);