Stabilize the Clipboard API

[evilpie]

Motivation

Currently the Clipboard API is in the unstable folder: https://github.com/rustwasm/wasm-bindgen/blob/main/crates/web-sys/webidls/unstable/Clipboard.webidl. Since Firefox 127 all browsers support this API in stable versions. There are still some difference like unsanitized where Safari/Firefox won't follow Chrome: https://github.com/w3c/clipboard-apis/issues/206#issue-2038753339.

Additionally this would be useful for Ruffle so we don't need to opt-in to unstable for https://github.com/ruffle-rs/ruffle/pull/16692.

Proposed Solution

I am going to make it stable.

Alternatives

n/a

Additional Context

https://developer.mozilla.org/en-US/docs/Web/API/Clipboard#browser_compatibility