chore(deps): bump actions/checkout from 4 to 5

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/release.yml

@@ -64,7 +64,7 @@ jobs:
           - mipsel-unknown-linux-musl
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: nightly

README.md

@@ -5,8 +5,7 @@ A lightweight and fast UDP to TCP obfuscator.
 ![GitHub Workflow Status](https://img.shields.io/github/actions/workflow/status/dndx/phantun/rust.yml)
 ![docs.rs](https://img.shields.io/docsrs/fake-tcp)
 
-Table of Contents
-=================
+# Table of Contents
 
 * [Phantun](#phantun)
 * [Latest release](#latest-release)
@@ -35,7 +34,7 @@ Table of Contents
 
 # Latest release
 
-[v0.8.0](https://github.com/dndx/phantun/releases/tag/v0.8.0)
+[v0.8.1](https://github.com/dndx/phantun/releases/tag/v0.8.1)
 
 <details>
   <summary>MIPS architecture support for Phantun</summary>