Fix Linux compilation failing due to infinite recursion

[itsjunetime]

Right now, on current main, I can't compile psst-gui due to an issue with overflowing trait requirements:

error[E0275]: overflow evaluating the requirement `sized_chunks::sized_chunk::Chunk<TrackLines>: std::marker::Sync`
   --> psst-gui/src/ui/search.rs:52:6
    |
52  |     .on_command_async(
    |      ^^^^^^^^^^^^^^^^
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`psst_gui`)
    = note: required for `std::sync::Arc<sized_chunks::sized_chunk::Chunk<TrackLines>>` to implement `Send`
note: required because it appears within the type `im::fakepool::Arc<sized_chunks::sized_chunk::Chunk<TrackLines>>`
   --> /home/june/.cargo/registry/src/index.crates.io-6f17d22bba15001f/im-15.1.0/./src/fakepool.rs:128:19
    |
128 | pub(crate) struct Arc<A>(RArc<A>);
    |                   ^^^
note: required because it appears within the type `im::nodes::rrb::Entry<TrackLines>`
   --> /home/june/.cargo/registry/src/index.crates.io-6f17d22bba15001f/im-15.1.0/./src/nodes/rrb.rs:162:6
    |
162 | enum Entry<A> {
    |      ^^^^^
note: required because it appears within the type `im::nodes::rrb::Node<TrackLines>`
   --> /home/june/.cargo/registry/src/index.crates.io-6f17d22bba15001f/im-15.1.0/./src/nodes/rrb.rs:244:19
    |
244 | pub(crate) struct Node<A> {
    |                   ^^^^
note: required because it appears within the type `sized_chunks::types::SizeOdd<im::nodes::rrb::Node<TrackLines>, ()>`
   --> /home/june/.cargo/registry/src/index.crates.io-6f17d22bba15001f/sized-chunks-0.6.5/src/types.rs:36:12
    |
36  | pub struct SizeOdd<A, B> {
    |            ^^^^^^^
note: required because it appears within the type `sized_chunks::types::SizeEven<im::nodes::rrb::Node<TrackLines>, sized_chunks::types::SizeOdd<im::nodes::rrb::Node<TrackLines>, ()>>`
   --> /home/june/.cargo/registry/src/index.crates.io-6f17d22bba15001f/sized-chunks-0.6.5/src/types.rs:28:12
    |
28  | pub struct SizeEven<A, B> {
    |            ^^^^^^^^
note: required because it appears within the type `sized_chunks::types::SizeEven<im::nodes::rrb::Node<TrackLines>, sized_chunks::types::SizeEven<im::nodes::rrb::Node<TrackLines>, sized_chunks::types::SizeOdd<im::nodes::rrb::Node<TrackLines>, ()>>>`

It seems that switching this Vector to an Arc<[]> fixes the compilation issue. It also runs fine and I've verified that I can listen to music and view lyrics and such with this change. I'm not super familiar with druid, so I'm not certain if this Vector is needed for any sort of reactivity or whatever, but it seems to work fine for me.

[jacksongoode]

Thanks for this, I just noticed it today as well!