Prepare v0.4.0 release (#798)

Author: dhardy

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [0.4.0] - 2026-02-02
 
 ### Added
 - `RawOsError` type alias [#739]

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "getrandom"
-version = "0.4.0-rc.1"
+version = "0.4.0"
 edition = "2024"
 rust-version = "1.85" # Sync tests.yml and README.md.
 authors = ["The Rand Project Developers"]
@@ -38,7 +38,7 @@ sys_rng = ["dep:rand_core"]
 
 [dependencies]
 cfg-if = "1"
-rand_core = { version = "0.10.0-rc-6", optional = true }
+rand_core = { version = "0.10.0", optional = true }
 
 # getrandom / linux_android_with_fallback
 [target.'cfg(all(any(target_os = "linux", target_os = "android"), not(any(all(target_os = "linux", target_env = ""), getrandom_backend = "custom", getrandom_backend = "linux_raw", getrandom_backend = "rdrand", getrandom_backend = "rndr"))))'.dependencies]