Fix future unreachable_patterns warnings.

These warnings currently on nightly will be unresolvable until Rust 1.82
is released, or <rust-lang/rust#129031> is
fixed in some other way. After Rust 1.82, we can simply delete these
match arms (and in fact replace the `match`es with `let`s, if we wish).

Author: kpreid

Diff for: all-is-cubes-desktop/src/glue/rerun_mesh.rs

@@ -4,14 +4,14 @@ use std::time::Instant;
 
 use itertools::Itertools as _;
 
-use all_is_cubes_render::camera::Camera;
 use all_is_cubes::euclid::{Point3D, Vector3D};
 use all_is_cubes::math::{Cube, GridCoordinate};
 use all_is_cubes::rerun_glue as rg;
 use all_is_cubes::space::Space;
 use all_is_cubes::time::DeadlineStd;
 use all_is_cubes::universe::Handle;
 use all_is_cubes_mesh as mesh;
+use all_is_cubes_render::camera::Camera;
 
 use mesh::dynamic::ChunkedSpaceMesh;
 use mesh::texture::NoTexture;
@@ -49,6 +49,7 @@ impl From<mesh::BlockVertex<NoTexture>> for Vertex {
             position: v.position.to_f32().to_array().into(),
             color: match v.coloring {
                 mesh::Coloring::Solid(color) => color.to_srgb8().into(),
+                #[allow(unreachable_patterns)] // TODO: Remove this arm after Rust 1.81
                 mesh::Coloring::Texture { .. } => unreachable!(),
             },
         }

Diff for: all-is-cubes-ui/src/ui_content/pages.rs

@@ -52,6 +52,7 @@ pub(super) fn new_paused_page(
             // TODO: quit_fn should be an async function, but we don't have a way to
             // kick off a “Quitting...” task yet.
             move || match quit_fn() {
+                #[allow(unreachable_patterns)] // TODO: Remove this arm after Rust 1.81
                 Ok(s) => match s {},
                 Err(_cancelled) => {