zcash_client_sqlite does not currently compile with --no-default-features

[daira]

$ cargo check --all-targets --no-default-features
[...]
error[E0432]: unresolved imports `maybe_rayon::prelude::IndexedParallelIterator`, `maybe_rayon::slice::ParallelSliceMut`
  --> zcash_client_sqlite/src/lib.rs:37:15
   |
37 |     prelude::{IndexedParallelIterator, ParallelIterator},
   |               ^^^^^^^^^^^^^^^^^^^^^^^ no `IndexedParallelIterator` in `prelude`
38 |     slice::ParallelSliceMut,
   |     ^^^^^^^^^^^^^^^^^^^^^^^ no `ParallelSliceMut` in `slice`
   |
help: a similar name exists in the module
   |
37 |     prelude::{IntoParallelIterator, ParallelIterator},
   |               ~~~~~~~~~~~~~~~~~~~~
help: a similar name exists in the module
   |
38 |     slice::ParallelSlice,
   |            ~~~~~~~~~~~~~

warning: unused import: `ParallelIterator`
  --> zcash_client_sqlite/src/lib.rs:37:40
   |
37 |     prelude::{IndexedParallelIterator, ParallelIterator},
   |                                        ^^^^^^^^^^^^^^^^
   |
   = note: `#[warn(unused_imports)]` on by default

error[E0599]: no method named `par_chunks_mut` found for struct `Vec<Option<(sapling_crypto::Node, Retention<BlockHeight>)>>` in the current scope
   --> zcash_client_sqlite/src/lib.rs:738:22
    |
738 |                     .par_chunks_mut(CHUNK_SIZE)
    |                      ^^^^^^^^^^^^^^
    |
    = help: items from traits can only be used if the trait is in scope
help: the following trait is implemented but not in scope; perhaps add a `use` for it:
    |
35  | use rayon::slice::ParallelSliceMut;
    |
help: there is a method with a similar name
    |
738 |                     .chunks_mut(CHUNK_SIZE)
    |                      ~~~~~~~~~~

Some errors have detailed explanations: E0432, E0599.
For more information about an error, try `rustc --explain E0432`.
warning: `zcash_client_sqlite` (lib) generated 1 warning
error: could not compile `zcash_client_sqlite` due to 2 previous errors; 1 warning emitted
warning: build failed, waiting for other jobs to finish...
warning: `zcash_client_sqlite` (lib test) generated 1 warning (1 duplicate)
error: could not compile `zcash_client_sqlite` due to 2 previous errors; 1 warning emitted

(Same with RUSTFLAGS='--cfg zcash_unstable="orchard"' cargo check --all-targets --no-default-features.)