Bump hashbrown to 0.15.2 and address deprecated coverage_helper useage (see rust-lang/rust#126721)

Author: nand-nor

Cargo.toml

@@ -12,13 +12,15 @@ rust-version = "1.71.1"
 
 [dependencies]
 dlv-list = { version = "0.5", default-features = false }
-hashbrown = { version = "0.14.0", default-features = false }
+hashbrown = { version = "0.15.2", default-features = false, features=["raw-entry"] }
 serde = { version = "1", optional = true, default-features = false }
 
 [features]
 default = ["std"]
 std = ["dlv-list/std"]
 
 [dev-dependencies]
-coverage-helper = "0.2.0"
 serde_test = "1.0.144"
+
+[lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(coverage_nightly)'] }

src/lib.rs

@@ -3,7 +3,7 @@
 //!
 //! See the type documentation for more information.
 
-#![cfg_attr(coverage_nightly, feature(coverage_attribute))]
+#![cfg_attr(all(coverage_nightly, test), feature(coverage_attribute))]
 #![cfg_attr(not(feature = "std"), no_std)]
 
 extern crate alloc;

src/list_ordered_multimap.rs

@@ -3524,8 +3524,8 @@ where
 
 #[allow(unused_results)]
 #[cfg(all(test, feature = "std"))]
+#[cfg_attr(coverage_nightly, coverage(off))]
 mod test {
-  use coverage_helper::test;
 
   use super::*;
 
@@ -5361,7 +5361,7 @@ mod test {
   #[test]
   fn test_dummy_hasher_finish() {
     let hasher = DummyHasher;
-    hasher.finish();
+    let _ = hasher.finish();
   }
 
   #[should_panic]

src/serde.rs

@@ -79,8 +79,9 @@ where
 
 #[allow(unused_results)]
 #[cfg(all(test, feature = "std"))]
+#[cfg_attr(coverage_nightly, coverage(off))]
 mod test {
-  use coverage_helper::test;
+
   use serde_test::{assert_de_tokens_error, assert_tokens, Token};
 
   use super::*;