Gamepad not working in Firefox in Linux
Hi,

I couldn't get my gamepad to work on Firefox. It works correctly in <https://gamepad-tester.com>, and it also works correctly when I try running a WASM-4 game in Chrome.

Details:
- Arch Linux with Plasma,
- WASM-4 2.5.0 (AUR package: `wasm4-bin 2.5.0-1`), but the same thing happens on <https://wasm4.org/play>,
- Firefox 102.0.1 (Arch package: `firefox 102.0.1-1`). Sadly I couldn't get WASM-4 to work at all in the Firefox troubleshooting mode, but I did disable extensions and nothing changed,
- gamepad is 8BitDo SN30 Pro+ detected by Gamepad Tester as `Xbox Wireless Controller 045e-02e0-8BitDo SN30 Pro+`,
- the only things I see in the console when running locally are
  ```
  Lit is in dev mode. Not recommended for production! See https://lit.dev/msg/dev-mode for more information. [reactive-element.js:38:20](http://localhost:4444/node_modules/@lit/reactive-element/development/reactive-element.js)
  Multiple versions of Lit loaded. Loading multiple versions is not recommended. See https://lit.dev/msg/multiple-versions for more information. [reactive-element.js:38:20](http://localhost:4444/devtools/web/node_modules/@lit/reactive-element/development/reactive-element.js)
  Warning: Cart is larger than 65536 bytes. Ensure the release build of your cart is small enough to be bundled. [runtime.ts:267:20](http://localhost:4444/src/runtime.ts)
  ```
  (the last one due to testing using `snake-rust`).

Due to my total ineptitude when it comes to webdev I haven't really investigated this too much. One thing that I did manage to find is that `navigator.getGamepads()` works differently across those two browsers: in Chrome it returns `[null, null, null, null]` (as shown by DevTools) before touching the gamepad and `[Gamepad, null, null, null]` afterwards, but in Firefox there are no `null`s: before touching the gamepad it returns `[]` and after touching `[Gamepad]`. This does feel relevant but I don't know.
