[Bug] Safari: non-https site reports undefined is not an object (evaluating 'navigator.clipboard.write')

[wxiaoguang]

Reproduction Steps

• Use monaco-editor on a "http" site (v0.48.0), (do not use localhost, use local IP like http://192.168.1.20)
• Use Safari to open the page, input anything
• Then navigator.clipboard.write triggers the bug

    installWebKitWriteTextWorkaround() {
        const handler = () => {
            ....
            navigator.clipboard.write([new ClipboardItem({ // !!!!!!!!!!!!!! BUG HERE !!!!!!!!!!!!!!!!!!!!!
                    'text/plain': currentWritePromise.p,
                })])
            ....
        };