uv-resolver: make PubGrubPackage orderable

It turns out that we use PubGrubPackage as the key in hashmaps in a fair
few places. And when we iterate over hashmaps, the order is unspecified.
This can in turn result in changes in output as a result of changes in
the PubGrubPackage definition, purely as a function of its changing
hash. This is confusing as there should be no semantic difference.

Thus, this is a precursor to introducing some more determinism to places
I found in the error reporting whose output depending on hashmap
iteration order.

crates/uv-git/src/git.rs

@@ -23,7 +23,7 @@ use crate::FetchStrategy;
 const CHECKOUT_READY_LOCK: &str = ".ok";
 
 /// A reference to commit or commit-ish.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub enum GitReference {
     /// A specific branch.
     Branch(String),

crates/uv-git/src/lib.rs

@@ -12,7 +12,7 @@ mod source;
 mod util;
 
 /// A URL reference to a Git repository.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Hash, Ord)]
 pub struct GitUrl {
     /// The URL of the Git repository, with any query parameters, fragments, and leading `git+`
     /// removed.