clippy: unnecessary_map_or

[brooksprumo]

Problem

New clippy lints when upgrading to rust 1.84.0.

warning: this `map_or` is redundant
   --> sdk/program/src/vote/state/mod.rs:702:12
    |
702 |           if self
    |  ____________^
703 | |             .last_voted_slot()
704 | |             .map_or(false, |last_voted_slot| next_vote_slot <= last_voted_slot)
    | |_______________________________________________________________________________^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_map_or
    = note: `#[warn(clippy::unnecessary_map_or)]` on by default
help: use is_some_and instead
    |
702 ~         if self
703 +             .last_voted_slot().is_some_and(|last_voted_slot| next_vote_slot <= last_voted_slot)

Summary of Changes

Resolve the lints by using the suggestions from clippy and checking the code.

Partially fixes #4380

[mergify]

The Firedancer team maintains a line-for-line reimplementation of the
native programs, and until native programs are moved to BPF, those
implementations must exactly match their Agave counterparts.
If this PR represents a change to a native program implementation (not
tests), please include a reviewer from the Firedancer team. And please
keep refactors to a minimum.

[brooksprumo]

This one is a tiny bit different:

warning: this `map_or` is redundant
  --> core/src/warm_quic_cache_service.rs:79:28
   |
79 |                           if maybe_last_leader
   |  ____________________________^
80 | |                             .map_or(true, |last_leader| last_leader != leader_pubkey)
   | |_____________________________________________________________________________________^ help: use a standard comparison instead: `(maybe_last_leader != Some(leader_pubkey))`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_map_or
   = note: `#[warn(clippy::unnecessary_map_or)]` on by default