Prepare 0.4.0 release

Use trusted publishing to turn a GitHub release into a crates.io
release.

Author: mciantyre

.github/workflows/release.yml

@@ -0,0 +1,18 @@
+name: Publish release to crates.io
+on:
+  release:
+    types: [ published ]
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    environment: release
+    permissions:
+      id-token: write
+    steps:
+    - uses: actions/checkout@v6
+    - uses: rust-lang/crates-io-auth-action@v1
+      id: auth
+    - run: rustup toolchain install stable --no-self-update --profile minimal
+    - run: cargo publish --package=imxrt-usbd --target=thumbv7em-none-eabihf --features=imxrt-ral/imxrt1011
+      env:
+        CARGO_REGISTRY_TOKEN: ${{ steps.auth.outputs.token }}

CHANGELOG.md

@@ -4,6 +4,9 @@ Changelog
 [Unreleased]
 ------------
 
+[0.4.0] 2026-04-12
+------------------
+
 The package now requires imxrt-ral to represent its register access layer.
 The `Peripherals` trait is gone, and users are expected to use imxrt-ral
 peripheral instances.
@@ -93,7 +96,8 @@ endpoints.
 
 First release
 
-[Unreleased]: https://github.com/imxrt-rs/imxrt-usbd/compare/v0.3.0...HEAD
+[Unreleased]: https://github.com/imxrt-rs/imxrt-usbd/compare/v0.4.0...HEAD
+[0.4.0]: https://github.com/imxrt-rs/imxrt-usbd/compare/v0.3.0...v0.4.0
 [0.3.0]: https://github.com/imxrt-rs/imxrt-usbd/compare/v0.2.2...v0.3.0
 [0.2.2]: https://github.com/imxrt-rs/imxrt-usbd/compare/v0.2.1...v0.2.2
 [0.2.1]: https://github.com/imxrt-rs/imxrt-usbd/compare/v0.2.0...v0.2.1