chore: make clippy happy

[fgimenez]

prevents warnings like these with latest clippy:

warning: this `continue` expression is redundant
   --> crates/ethereum-forks/src/display.rs:163:41
    |
163 |                 ForkCondition::Never => continue,
    |                                         ^^^^^^^^
    |
    = help: consider dropping the `continue` expression
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_continue
    = note: requested on the command line with `-W clippy::needless-continue`

warning: `reth-chainspec` (lib) generated 1 warning
warning: length comparison to zero
   --> crates/trie/sparse/src/trie.rs:820:49
    |
820 | ...                   hash.filter(|_| path.len() == 0),
    |                                       ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `path.is_empty()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
    = note: `#[warn(clippy::len_zero)]` on by default

warning: called `Iterator::last` on a `DoubleEndedIterator`; this will needlessly iterate the entire iterator
    --> crates/storage/provider/src/providers/blockchain_provider.rs:1870:18
     |
1870 |                 .last()
     |                  ^^^^^^ help: try: `next_back()`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#double_ended_iterator_last
     = note: `#[warn(clippy::double_ended_iterator_last)]` on by default

[DaniPopes]

lgtm