[Rust codegen] Incorrectly derives Eq trait for types containing f64 fields

[Rhovian]

Problem

When an IDL contains event types with "type": "f64" fields, the generated Rust code fails to compile:

eg;

```rust
#[derive(BorshSerialize, BorshDeserialize, Clone, Debug, Eq, PartialEq)]
pub struct LendingAccountLiquidateEvent {
    pub liquidatee_pre_health: f64,
    pub liquidatee_post_health: f64,
    ...
}

error[E0277]: the trait bound `f64: std::cmp::Eq` is not satisfied
  --> clients/rust/src/generated/types/lending_account_liquidate_event.rs:30:1

Root Cause

f64 cannot implement Eq because of NaN handling (NaN != NaN). The Rust compiler only allows Eq for types where equality is reflexive, symmetric, and transitive.

Happy to PR a solution to this if no one is working on it.

[lorisleiva]

Hi, thanks for raising this. Finding the right set of default traits that suits most situations is pretty tricky. An immediate workaround is to use traitOptions in the configuration of the renderer.

One way to fix this could be to dynamically change the default traits based on the content of the struct but I'm worried this will create unpredictable behaviour for developers and confuse them even more.

We could also remove Eq from the default set instead.