[Bug] Copy/pasting multiline content with key:value format in Safari loses line breaks

Reproducible in vscode.dev or in VS Code Desktop?

• Not reproducible in vscode.dev or VS Code Desktop

Reproducible in the monaco editor playground?

• Not reproducible in the monaco editor playground

Monaco Editor Playground Link

https://microsoft.github.io/monaco-editor/playground.html?source=v0.38.0#XQAAAAKiAQAAAAAAAABBqQkHQ5NjdMjwa-jY7SIQ9S7DNlzs5W-mwj0fe1ZCDRFc9ws9XQE0SJE1jc2VKxhaLFIw9vEWSxW3yscwzwauRgmSaumWUF-TBOsVJ4S4FwfCDQb5-2uUHXTVAefbVSd9IzaZ_vv9VR9KugsKioBUYGa0XsnArxmHPolFj8CfzECMW-192L1d0AxNn3frXdATDcOjBDBCfFOP9lxPkDGa94bLCQjig1WeZ-XvLSWLvYAoeBgnD9Y-1FkIZ4ZiDBKGGWqsmNGpBJpSH-BkEAWx_SluutEVJnITCjgHGAPrMlGP_KrBAt_DqFjnhfj3mYSAZ-bePmjIwVfhU3YEf8b4BH-liLT398A8AkESSXsvlH-B47fMM6Pd2k2ONI-s-gNELRvux_997GgA

Monaco Editor Playground Code

const value = /* set from `myEditor.getModel()`: */ `key: thing
otherkey: stuff
foo: bar

key : thing
otherkey : stuff
foo : bar

---
key: thing
otherkey: stuff
foo: bar

`;

// Hover on each property to see its docs!
const myEditor = monaco.editor.create(document.getElementById("container"), {
	value,
	language: "yaml",
	automaticLayout: true,
});

Reproduction Steps

In Safari on MacOS, select multiple lines of text which are of the format key: value, and then paste in a plain text setting, e.g. VSCode, TextEdit, etc. Observe that the text is pasted without line endings - i.e. all on one line.

Note: If pasting into a rich text setting such as Notes app or another Monaco Editor then line endings are correctly preserved.

Actual (Problematic) Behavior

Text is pasted without line breaks.

https://github.com/microsoft/monaco-editor/assets/1550045/404a2e30-595c-47a1-b492-a931526ae516

Expected Behavior

Text is pasted with line breaks in tact.

Additional Context

Safari: Version 16.4 (18615.1.26.110.1)
MacOS: 13.3.1 (a)

Start with the Monaco Editor Playground link and the provided TypeScript reproduction, then reproduce the paste behavior in Safari using plain-text and rich-text targets. Trace the editor's clipboard handling for multiline key:value content. Done means pasting into a plain-text setting preserves all line breaks while the existing rich-text behavior remains correct.