v2.1: supress hashbrown audit (#3920)

ci/do-audit.sh

@@ -59,6 +59,17 @@ cargo_audit_ignores=(
   # Dependency tree:
   # rustls 0.23.17
   --ignore RUSTSEC-2024-0399
+
+  # Crate:     hashbrown
+  # Version:   0.15.0
+  # Title:     Borsh serialization of HashMap is non-canonical
+  # Date:      2024-10-11
+  # ID:        RUSTSEC-2024-0402
+  # URL:       https://rustsec.org/advisories/RUSTSEC-2024-0402
+  # Solution:  Upgrade to >=0.15.1
+  # Dependency tree:
+  # hashbrown 0.15.0
+  --ignore RUSTSEC-2024-0402
 )
 scripts/cargo-for-all-lock-files.sh audit "${cargo_audit_ignores[@]}" | $dep_tree_filter
 # we want the `cargo audit` exit code, not `$dep_tree_filter`'s