Disable rand_pcg's dev dependency on rand (#1397)

The circular dependency prevents publishing

Author: dhardy

rand_pcg/Cargo.toml

@@ -26,7 +26,6 @@ rand_core = { path = "../rand_core", version = "=0.9.0-alpha.0" }
 serde = { version = "1", features = ["derive"], optional = true }
 
 [dev-dependencies]
-rand = { path = "..", version = "=0.9.0-alpha.0" }
 # This is for testing serde, unfortunately we can't specify feature-gated dev
 # deps yet, see: https://github.com/rust-lang/cargo/issues/1596
 # Versions prior to 1.1.4 had incorrect minimal dependencies.

rand_pcg/src/lib.rs

@@ -43,7 +43,7 @@
 //! The functionality of this crate is implemented using traits from the `rand_core` crate, but you may use the `rand`
 //! crate for further functionality to initialize the generator from various sources and to generate random values:
 //!
-//! ```
+//! ```ignore
 //! use rand::{Rng, SeedableRng};
 //! use rand_pcg::Pcg64Mcg;
 //!