libportal: upgrade 0.8.1 -> 0.9.0

libportal: upgrade 0.8.1 -> 0.9.0

Changelog:
===========
Dependencies:
- GLib 2.72 or higher is now required

Features:
- Introduce support for the Notification v2 portal version

Bug fixes:
- Fix a file descriptor leak in the Mail portal code
- Fix some minor memory leaks

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>