Update to objc2 v0.6

This includes using the new crate `objc2-core-graphics`, which notably
does not have the `CustomData` helper that `core-graphics`. This is
probably for the better, as it allows us to avoid a double-boxing of the
data.

Cargo.toml

@@ -1,7 +1,11 @@
 [package]
 name = "arboard"
 version = "3.4.1"
-authors = ["Artur Kovacs <[email protected]>", "Avi Weinstock <[email protected]>", "Arboard contributors"]
+authors = [
+    "Artur Kovacs <[email protected]>",
+    "Avi Weinstock <[email protected]>",
+    "Arboard contributors",
+]
 description = "Image and text handling for the OS clipboard."
 repository = "https://github.com/1Password/arboard"
 license = "MIT OR Apache-2.0"
@@ -12,7 +16,12 @@ rust-version = "1.67.1"
 
 [features]
 default = ["image-data"]
-image-data = ["core-graphics", "image", "windows-sys"]
+image-data = [
+    "objc2-core-graphics",
+    "objc2-core-foundation",
+    "image",
+    "windows-sys",
+]
 wayland-data-control = ["wl-clipboard-rs"]
 
 [dependencies]
@@ -27,24 +36,50 @@ windows-sys = { version = "0.48.0", optional = true, features = [
     "Win32_System_DataExchange",
     "Win32_System_Memory",
     "Win32_System_Ole",
-]}
+] }
 clipboard-win = "5.3.1"
 log = "0.4"
-image = { version = "0.25", optional = true, default-features = false, features = ["png"] }
+image = { version = "0.25", optional = true, default-features = false, features = [
+    "png",
+] }
 
 [target.'cfg(target_os = "macos")'.dependencies]
-# Use `relax-void-encoding`, as that allows us to pass `c_void` instead of implementing `Encode` correctly for `&CGImageRef`
-objc2 = { version = "0.5.1", features = ["relax-void-encoding"] }
-objc2-foundation = { version = "0.2.0", features = ["NSArray", "NSString", "NSEnumerator", "NSGeometry"] }
-objc2-app-kit = { version = "0.2.0", features = ["NSPasteboard", "NSPasteboardItem", "NSImage"] }
-core-graphics = { version = "0.23", optional = true }
-image = { version = "0.25", optional = true, default-features = false, features = ["tiff"] }
+objc2 = "0.6.0"
+objc2-foundation = { version = "0.3.0", default-features = false, features = [
+    "std",
+    "NSArray",
+    "NSString",
+    "NSEnumerator",
+    "NSGeometry",
+] }
+objc2-app-kit = { version = "0.3.0", default-features = false, features = [
+    "std",
+    "objc2-core-graphics",
+    "NSPasteboard",
+    "NSPasteboardItem",
+    "NSImage",
+] }
+objc2-core-foundation = { version = "0.3.0", default-features = false, optional = true, features = [
+    "std",
+    "CFCGTypes",
+] }
+objc2-core-graphics = { version = "0.3.0", default-features = false, optional = true, features = [
+    "std",
+    "CGImage",
+    "CGColorSpace",
+    "CGDataProvider",
+] }
+image = { version = "0.25", optional = true, default-features = false, features = [
+    "tiff",
+] }
 
 [target.'cfg(all(unix, not(any(target_os="macos", target_os="android", target_os="emscripten"))))'.dependencies]
 log = "0.4"
 x11rb = { version = "0.13" }
 wl-clipboard-rs = { version = "0.8", optional = true }
-image = { version = "0.25", optional = true, default-features = false, features = ["png"] }
+image = { version = "0.25", optional = true, default-features = false, features = [
+    "png",
+] }
 parking_lot = "0.12"
 
 [[example]]