cargo: prepare ostree 0.16.0 and ostree-sys 0.11.0

This prepares for a new release of both crates, now using the
gtk-rs 0.15 stack.

rust-bindings/sys/Cargo.toml

@@ -82,7 +82,7 @@ license = "MIT"
 links = "ostree-1"
 name = "ostree-sys"
 repository = "https://github.com/ostreedev/ostree-rs"
-version = "0.10.0"
+version = "0.11.0"
 edition = "2021"
 [package.metadata.docs.rs]
 features = ["dox"]