ci(chain): downgrade hashbrown dependency to 0.9.1 to fix ahash related MSRV issue

Author: notmandatory

crates/chain/Cargo.toml

@@ -18,8 +18,8 @@ bitcoin = { version = "0.30.0", default-features = false }
 serde_crate = { package = "serde", version = "1", optional = true, features = ["derive"] }
 
 # Use hashbrown as a feature flag to have HashSet and HashMap from it.
-# note version 0.13 breaks outs MSRV.
-hashbrown = { version = "0.11", optional = true, features = ["serde"] }
+# note versions > 0.9.1 breaks ours 1.57.0 MSRV.
+hashbrown = { version = "0.9.1", optional = true, features = ["serde"] }
 miniscript = { version = "10.0.0", optional = true, default-features = false }
 
 [dev-dependencies]