Red Knot Playground (#12681)

## Summary

This PR adds a playground for Red Knot

[Screencast from 2024-08-14
10-33-54.webm](https://github.com/user-attachments/assets/ae81d85f-74a3-4ba6-bb61-4a871b622f05)

Sharing does work 😆 I just forgot to start wrangler. 


It supports:

* Multiple files
* Showing the AST
* Showing the tokens
* Sharing
* Persistence to local storage

Future extensions:

* Configuration support: The `pyproject.toml` would *just* be another
file.
* Showing type information on hover

## Blockers

~~Salsa uses `catch_unwind` to break cycles, which Red Knot uses
extensively when inferring types in the standard library.
However, WASM (at least `wasm32-unknown-unknown`) doesn't support
`catch_unwind` today, so the playground always crashes when the type
inference encounters a cycle.~~

~~I created a discussion in the [salsa
zulip](https://salsa.zulipchat.com/#narrow/stream/333573-salsa-3.2E0/topic/WASM.20support)
to see if it would be possible to **not** use catch unwind to break
cycles.~~

~~[Rust tracking issue for WASM catch unwind
support](https://github.com/rust-lang/rust/issues/118168)~~

~~I tried to build the WASM with the nightly compiler option but ran
into problems because wasm-bindgen doesn't support WASM-exceptions. We
could try to write the binding code by hand.~~

~~Another alternative is to use `wasm32-unknown-emscripten` but it's
rather painful to build~~

.github/workflows/ci.yaml

@@ -736,10 +736,9 @@ jobs:
       - name: "Install Node dependencies"
         run: npm ci
         working-directory: playground
-      - name: "Build Ruff playground"
-        run: npm run dev:build --workspace ruff-playground
+      - name: "Build playgrounds"
+        run: npm run dev:wasm
         working-directory: playground
-        # Requires a build for ruff_wasm to exist
       - name: "Run TypeScript checks"
         run: npm run check
         working-directory: playground

.github/workflows/publish-playground.yml

@@ -38,12 +38,12 @@ jobs:
       - name: "Install Node dependencies"
         run: npm ci
         working-directory: playground
-      - name: "Build Ruff playground"
-        run: npm run build --workspace ruff-playground
-        working-directory: playground
       - name: "Run TypeScript checks"
         run: npm run check
         working-directory: playground
+      - name: "Build Ruff playground"
+        run: npm run build --workspace ruff-playground
+        working-directory: playground
       - name: "Deploy to Cloudflare Pages"
         if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
         uses: cloudflare/wrangler-action@da0e0dfe58b7a431659754fdf3f186c529afbe65 # v3.14.1