build: drop the wgpu and bytemuck declarations this crate never used

Leftovers from the retired wgpu rendering path. Nothing in this crate
names wgpu and bytemuck — not in src/, tests, or a build script. cce-ui renders
with raw Vulkan via ash, and clients only ever hand it display lists.

Manifest hygiene rather than a build-time saving: both still compile as
transitive dependencies (wgpu via glyphon, bytemuck via cce-ui and image
among others). What goes away is the false claim that this crate talks
to a GPU API directly.

Part of a workspace-wide sweep of the same dead declarations, which sat
in 13 crates (wgpu) and 14 (bytemuck). cce-designer and cce-ui keep
bytemuck — they genuinely use it.

 Cargo.toml | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index b680847..c3430d3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,8 +6,6 @@ edition = "2021"
 [dependencies]
 cce-ui = { path = "../cce-ui" }
 raw-window-handle = "0.6"
-wgpu = "24"
-bytemuck = { version = "1", features = ["derive"] }
 pollster = "0.4"
 glyphon = "0.8"
 tokio = { version = "1", features = ["full"] }