message: [pdsl_core] Remove memory::HashMap and memory::HashSet
  From previous commit:
  The problem with memory::Hash{Map,Set} is that it is not compatible with no_std environments.
  It requires random state which is currently not a thing in the SRML and also it might use floats internally (e.g. for fill rate) which are also currently disabled due to non-determinism.
diff: @@ -12,15 +12,12 @@ mod no_std_defs {
  /// Collection types.
  pub mod collections {
  pub use alloc::collections::*;
  - pub use hashbrown::{hash_map, hash_set};
  pub use self::{
  BinaryHeap,
  BTreeMap,
  BTreeSet,
  LinkedList,
  VecDeque,
  - hash_map::HashMap,
  - hash_set::HashSet,
  };
  pub use core::ops::Bound;
  }
  @@ -42,8 +39,6 @@ mod std_defs {
  btree_set::BTreeSet,
  linked_list::LinkedList,
  vec_deque::VecDeque,
  - hash_map::HashMap,
  - hash_set::HashSet,
  Bound,
  };
  }
  