chore(ci): Check for clippy correctness (#14796)

### What does this PR try to resolve?

The fact that we don't check for `derive_ord_xor_partial_ord ` almost
bit us in #14663. If we used clippy's default lint levels, this would
have been caught automatically.

Instead of just enabling this one lint, I figured it'd be good to audit
all of the `deny` by default lints.
That is long enough that I was concerned about maintaining it (or
bikeshedding which to enable or disable).
All `deny` by default lints are `correctness` lints and I figure we
could just enable the group.

We normally opt-in to individual clippy lints.
From what I remember of that conversation, it mostly stems from how
liberal clippy is with making a lint `warn` by default.
It also makes an unpinned CI more brittle.
I figured clippy is more conservative about `deny` by default lints
and slower to add them that this is unlikely to be a problem.

As for what existing problems this found,
- Some missing serde functions that would be useful for formats besides
toml (since `toml` never uses borrowed strings)
- Code that behaves differently than the syntax says (a 0-1 iteration
loop)
- A redundant assignment (wasn't even removing `mut`ness

### How should we test and review this PR?

### Additional information

Cargo.toml

@@ -121,7 +121,8 @@ rust_2018_idioms = "warn" # TODO: could this be removed?
 private_intra_doc_links = "allow"
 
 [workspace.lints.clippy]
-all = { level = "allow", priority = -1 }
+all = { level = "allow", priority = -2 }
+correctness = { level = "warn", priority = -1 }
 dbg_macro = "warn"
 disallowed_methods = "warn"
 print_stderr = "warn"

crates/cargo-util-schemas/src/manifest/mod.rs

@@ -418,6 +418,13 @@ impl<'de> de::Deserialize<'de> for InheritableString {
                 Ok(InheritableString::Value(value))
             }
 
+            fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+            where
+                E: de::Error,
+            {
+                self.visit_string(value.to_owned())
+            }
+
             fn visit_map<V>(self, map: V) -> Result<Self::Value, V::Error>
             where
                 V: de::MapAccess<'de>,
@@ -454,6 +461,13 @@ impl<'de> de::Deserialize<'de> for InheritableRustVersion {
                 Ok(InheritableRustVersion::Value(value))
             }
 
+            fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+            where
+                E: de::Error,
+            {
+                self.visit_string(value.to_owned())
+            }
+
             fn visit_map<V>(self, map: V) -> Result<Self::Value, V::Error>
             where
                 V: de::MapAccess<'de>,
@@ -533,6 +547,13 @@ impl<'de> de::Deserialize<'de> for InheritableStringOrBool {
                 StringOrBool::deserialize(string).map(InheritableField::Value)
             }
 
+            fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+            where
+                E: de::Error,
+            {
+                self.visit_string(value.to_owned())
+            }
+
             fn visit_map<V>(self, map: V) -> Result<Self::Value, V::Error>
             where
                 V: de::MapAccess<'de>,

crates/rustfix/src/replace.rs

@@ -255,6 +255,7 @@ mod tests {
     }
 
     #[test]
+    #[allow(clippy::reversed_empty_ranges)]
     fn replace_invalid_range() {
         let mut d = Data::new(b"foo!");
 

src/cargo/core/resolver/dep_cache.rs

@@ -207,7 +207,6 @@ impl<'a> RegistryQueryer<'a> {
             }
         }
 
-        let first_version = first_version;
         self.version_prefs.sort_summaries(&mut ret, first_version);
 
         let out = Poll::Ready(Rc::new(ret));

src/cargo/util/mod.rs

@@ -176,8 +176,8 @@ mod test {
         );
         assert_eq!(human_readable_bytes(1024 * 1024 * 1024), (1., "GiB"));
         assert_eq!(
-            human_readable_bytes((1024. * 1024. * 1024. * 3.1415) as u64),
-            (3.1415, "GiB")
+            human_readable_bytes((1024. * 1024. * 1024. * 1.2345) as u64),
+            (1.2345, "GiB")
         );
         assert_eq!(human_readable_bytes(1024 * 1024 * 1024 * 1024), (1., "TiB"));
         assert_eq!(

src/cargo/util/toml/mod.rs

@@ -507,7 +507,7 @@ fn normalize_toml(
 
         normalized_toml.badges = original_toml.badges.clone();
     } else {
-        for field in original_toml.requires_package() {
+        if let Some(field) = original_toml.requires_package().next() {
             bail!("this virtual manifest specifies a `{field}` section, which is not allowed");
         }
     }