Update all the things for Guzzle 7 (php8 compat)
Update all the things for Guzzle 7 (php8 compat)

Guzzle 6 doesn't support php8, hence we need this for 21 for full php8
support.

Signed-off-by: Christoph Wurst <7abde52c298496fa169fb750f91f213a282142af@winzerhof-wurst.at>

nextcloud/server,nextcloud/server,nextcloud/server,nextcloud/server