greetd 0.10.0

This release contains breaking changes:

1. Support for the old configuration format, superseded in 0.5.0, has
   been removed. Please ensure that the new INI format documented in
   `man 5 greetd` is used before upgrading.

2. Support for falling back to the `login` PAM service when the `greetd`
   PAM service is missing has been removed. Ensure that a `greetd` PAM
   service is present in `/etc/pam.d/` or `/usr/lib/pam.d` before
   upgrading. The file for `login` can be copied if the fallback was
   used previously.

3. Fewer environment variables are exposed to user sessions. In
   particular, GREETD_SOCK is only shown to greeter sessions, and
   XDG_SESSION_CLASS and XDG_VTNR is only shown to PAM.

greetd now supports the `/usr/lib/pam.d` service folder, and using a
different PAM service file for greeter and user sessions. If a service
file named "greetd-greeter" is present, this will be used for the
greeter session, while "greetd" is used for the user session. The
service file can also be configured in the general, default_session and
initial_session sections through the "service" setting.

Aleksei Bavshin (1):
      Update deprecated SPDX identifier for GPL-3.0-only

Arnaud Ferraris (1):
      config: allow using custom PAM configs

Harish Rajagopal (1):
      Add ReGreet to list of known greetd greeters

Hugo Osvaldo Barrera (8):
      Drop unmaintained `users` crate
      Remove no-op question mark and Ok()
      Remove references that are implicitly dereferenced
      Remove pointless copying of string before copying it
      Use strip_prefix to strip prefix
      Derive VtSelection::default
      Deduplicate parsing of VtSelection
      Allow overriding VT via arguments

Jonathan Sköld (1):
      agreety: Return error if no input when prompted

Kenny Levinsen (14):
      config: Fix tests for service config
      server: cargo fmt
      Minimize user-exposed environment variables
      cargo update
      Update dependencies
      pam: Check /usr/lib/pam.d
      pam: Remove fallback to the login service
      pam: Swap /etc/pam.d and /usr/lib/pam.d
      agreety: Update nix to 0.27
      config: Drop support for old config format
      man: Document VT switch
      Update dependencies
      Update dependencies
      Bump version to 0.10

ShootingStarDragons (2):
      chore: set dir to absolute path
      readme: Add two greeter implementations

fossdd (1):
      readme: Add Phog greeter implementation