New ostree-rs{,-ext} releases

["Colin Walters" <walters verbum org>]

ostree is a C library, as well as two Rust crates.
This is a release announcement for the Rust crates:

https://crates.io/crates/ostree/0.12.2

We didn't post 0.12.1 to the list, so this diff includes that.  Of note is we fixed the brown paper bag bug 
of breaking the build with --features=v2021_3, and the docs.rs build at https://docs.rs/ostree/0.12.2/ostree/ 
now works via feature flag sorcery.

git shortlog --no-merges v0.12.0..
Colin Walters (8):
      Add 2021.3 feature
      Re-export glib, gio
      Deny unused results, warn on missing docs (except auto/)
      Add new GLib 0.14 variant types for metadata types
      Fix build with --features=v2021_3, use in CI by default
      Add more documentation for --features=v2021_3
      Use glib-sys via re-exported `glib::ffi` (and similar for gio)
      Release 0.12.2

Luca BRUNO (5):
      cargo: fix version in features chain
      lib: fix 'dox' feature
      cargo: point to docs.rs and clean up
      ostree: release 0.12.1
      cargo: bump ostree-sys to 0.8.1

https://crates.io/crates/ostree-ext/0.2.2

Most notably this one is now also on docs.rs: https://docs.rs/ostree-ext/0.2.2/ostree_ext/ 

Colin Walters (8):
      oci: Pass through other architectures
      Use glib-sys via re-exported glib::ffi
      Use `glib` via re-export from `gio`
      ima: Use new GVariant code, drop unsafe
      Use gio via `ostree::gio`
      Try to fix the docs.rs build
      Re-export our dependencies (`ostree`, `gio`, `glib`) and add a prelude
      Release 0.2.2

Luca BRUNO (1):
      cargo: fix repository location