`filesUploadV2` needs `thread_ts`

[matthewnessworthy]

In the original filesUpload method there was the option to send through thread_ts. Ideally this would be possible with filesUploadV2 too.

[damienalexandre]

We have it in our patched schema:

https://github.com/jolicode/slack-php-api/blob/59e617a0176f5d9579dc0ee935c8aeaa0e74c31c/resources/slack-openapi-patched.json#L16886

As well as in the endpoint:

https://github.com/jolicode/slack-php-api/blob/59e617a0176f5d9579dc0ee935c8aeaa0e74c31c/generated/Endpoint/FilesCompleteUploadExternal.php#L30

So I assume it's just about making all the options available in this method:

https://github.com/jolicode/slack-php-api/blob/59e617a0176f5d9579dc0ee935c8aeaa0e74c31c/src/Client.php#L159-L167

Would you be able to submit a PR for this?

[matthewnessworthy]

I can, but the current method signature is quite different to all the other slack methods, so it would end up being a breaking change to do it right