Remove auto traits from ICE work-around

[brooksprumo]

Problem

#23295 added auto traits to BuiltinFeatureTransition to work around Rust issue rust-lang/rust#92987. This bug was fixed in Rust v1.60.0, which is the version we use, so this work-around can be removed.

solana/runtime/src/builtins.rs

Lines 94 to 110 in e344c84

	// https://github.com/solana-labs/solana/pull/23233 added `BuiltinFeatureTransition`
	// to `Bank` which triggers https://github.com/rust-lang/rust/issues/92987 while
	// attempting to resolve `Sync` on `BankRc` in `AccountsBackgroundService::new` ala,
	//
	// query stack during panic:
	// #0 [evaluate_obligation] evaluating trait selection obligation `bank::BankRc: core::marker::Sync`
	// #1 [typeck] type-checking `accounts_background_service::<impl at runtime/src/accounts_background_service.rs:358:1: 520:2>::new`
	// #2 [typeck_item_bodies] type-checking all item bodies
	// #3 [analysis] running analysis passes on this crate
	// end of query stack
	//
	// Yoloing a `Sync` onto it avoids the auto trait evaluation and thus the ICE.
	//
	// We should remove this when upgrading to Rust 1.60.0, where the bug has been
	// fixed by https://github.com/rust-lang/rust/pull/93064
	unsafe impl Send for BuiltinFeatureTransition {}
	unsafe impl Sync for BuiltinFeatureTransition {}

Summary of Changes

Remove work-around from #23295 and #23321.

[brooksprumo]

Should #23321 be reverted as well?

Edit: Reverting it too.