feat(next/image)!: remove `squoosh` in favor of `sharp` as optional dep (#61696)
## History
Previously, we added support for `squoosh` because it was a wasm
implementation that "just worked" on all platforms when running `next
dev` for the first time. However, it was slow so we always recommended
manually installing `sharp` for production use cases running `next
build` and `next start`.
Now that [`sharp` supports
webassembly](https://sharp.pixelplumbing.com/install#webassembly), we no
longer need to maintain `squoosh`, so it can be removed. We also don't
need to make the user install sharp manually because it can be installed
under `optionalDependencies`. I left it optional in case there was some
platform that still needed to manually install the wasm variant with
`npm install --cpu=wasm32 sharp` such as codesandbox/stackblitz (I don't
believe sharp has any fallback built in yet).
Since we can guarantee `sharp`, we can also remove `get-orientation` dep
and upgrade `image-size` dep.
I also moved an [existing `sharp`
test](https://github.com/vercel/next.js/pull/56674) into its own fixture
since it was unrelated to image optimization.
## Related Issues
- Fixes https://github.com/vercel/next.js/issues/41417
- Closes https://github.com/vercel/next.js/pull/54670
- Related https://github.com/vercel/next.js/issues/54708
- Related https://github.com/vercel/next.js/issues/44804
- Related https://github.com/vercel/next.js/issues/48820