rustlib: Use rust 1.83.0

One of the many Apple build changes madsmtm introduced in rustc
v1.82.0..v1.83.0 fixes linker issues when cross compiling from macOS to
iOS.

Likely candidates:
- rust-lang/rust#130435
- rust-lang/rust#131016

Author: dongcarl

rustlib/rust-toolchain.toml

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "1.80.1"
+channel = "1.83.0"
 components = [ "rustfmt" ]