Remove arrow from re_renderer

Cargo.lock

@@ -6308,7 +6308,6 @@ dependencies = [
  "pathdiff",
  "pollster 0.4.0",
  "profiling",
- "re_arrow2",
  "re_build_tools",
  "re_error",
  "re_log",

crates/viewer/re_renderer/Cargo.toml

@@ -33,9 +33,6 @@ ignored = ["profiling"] # Needed to hook up wgpu, see below at dependency setup.
 [features]
 default = ["import-obj", "import-gltf", "import-stl"]
 
-## Support for Arrow datatypes for end-to-end zero-copy.
-arrow = ["dep:arrow2"]
-
 ## Support importing .obj files
 import-obj = ["dep:tobj"]
 
@@ -83,7 +80,6 @@ wgpu.workspace = true
 wgpu-core.workspace = true                                           # Needed for error handling when wgpu-core implemented backend is used.
 
 # optional
-arrow2 = { workspace = true, optional = true }
 gltf = { workspace = true, optional = true }
 tinystl = { workspace = true, features = ["bytemuck"], optional = true }
 serde = { workspace = true, features = ["derive"], optional = true }

crates/viewer/re_renderer/src/lib.rs

@@ -98,16 +98,6 @@ pub mod external {
 
 // ---------------------------------------------------------------------------
 
-// Make Arrow integration as transparent as possible.
-
-#[cfg(feature = "arrow")]
-pub type Buffer<T> = arrow2::buffer::Buffer<T>;
-
-#[cfg(not(feature = "arrow"))]
-pub type Buffer<T> = Vec<T>;
-
-// ---------------------------------------------------------------------------
-
 /// Pad `RGB` to `RGBA` with the given alpha.
 pub fn pad_rgb_to_rgba<T: Copy>(rgb: &[T], alpha: T) -> Vec<T> {
     re_tracing::profile_function!();

crates/viewer/re_viewport/Cargo.toml

@@ -24,7 +24,6 @@ re_entity_db.workspace = true
 re_log_types.workspace = true
 re_log.workspace = true
 re_renderer = { workspace = true, default-features = false, features = [
-  "arrow",
   "import-gltf",
   "import-obj",
   "serde",