chore(manager): remove duplicate lit module

[daniellacosse]

current findings:

1. tried all the stuff in https://lit.dev/docs/tools/development/, didn't work for getting rid of the multiple dependencies, but gave useful context.
2. Then I had the idea to use npm's override feature instead - at first to force all our dependencies to use lit@3 and @lit/[email protected]. This didn't work as npm can't force versions upon dependencies that those dependencies don't accept:

3. Then I tried using override to enforce [email protected] instead, as it seemed that was the version all our dependencies would accept:

As you can see, this successfully removed the multiple versions of lit warning from the tests!

4. However, the app broke. The "new key" dialog freezes when you edit it, similar to how the rename dialog did before we used the mwc component as a workaround. This further lends credence to the idea that @material/web (the more modern md prefixed web components) don't play well with the older lit versions and that upgrading to 3 will ultimately fix this issue.

---

At this point, I think our only option is to use Webpack to force resolution of lit throughout our build (something I was trying to avoid):

const path = require('path');

module.exports = {
  // ... other webpack configurations
  resolve: {
    alias: {
      // This will make sure that any dependency that imports 'lit' or any of its sub-modules
      // will use the version you installed in step 1
      lit: path.resolve(__dirname, 'node_modules/lit'),
      'lit/*': path.resolve(__dirname, 'node_modules/lit/*'),
    },
  },
};

This is a little tricky given our monorepo structure, but doable.

Out of scope would be to switch back to yarn, as yarn 2+ has really precise controls for managing the dependencies of your dependencies.

Also, we should probably let the lit team (?) know about the overrides trick I discovered? That way they can update their documentation to be more helpful.