Drop support for Go 1.21 (#5736)

Co-authored-by: Sam Xie <sam@samxie.me>
Co-authored-by: Chester Cheung <cheung.zhy.csu@gmail.com>

.github/workflows/ci.yml

@@ -118,7 +118,7 @@ jobs:
   compatibility-test:
     strategy:
       matrix:
-        go-version: ["1.23.0", "~1.22.5", "~1.21.12"]
+        go-version: ["1.23.0", "~1.22.5"]
         platform:
           - os: ubuntu-latest
             arch: "386"

CHANGELOG.md

@@ -8,6 +8,10 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Removed
+
+- Drop support for [Go 1.21]. (#5736)
+
 <!-- Released section -->
 <!-- Don't change this section unless doing release -->
 

README.md

@@ -51,25 +51,18 @@ Currently, this project supports the following environments.
 |----------|------------|--------------|
 | Ubuntu   | 1.23       | amd64        |
 | Ubuntu   | 1.22       | amd64        |
-| Ubuntu   | 1.21       | amd64        |
 | Ubuntu   | 1.23       | 386          |
 | Ubuntu   | 1.22       | 386          |
-| Ubuntu   | 1.21       | 386          |
 | Linux    | 1.23       | arm64        |
 | Linux    | 1.22       | arm64        |
-| Linux    | 1.21       | arm64        |
 | macOS 13 | 1.23       | amd64        |
 | macOS 13 | 1.22       | amd64        |
-| macOS 13 | 1.21       | amd64        |
 | macOS    | 1.23       | arm64        |
 | macOS    | 1.22       | arm64        |
-| macOS    | 1.21       | arm64        |
 | Windows  | 1.23       | amd64        |
 | Windows  | 1.22       | amd64        |
-| Windows  | 1.21       | amd64        |
 | Windows  | 1.23       | 386          |
 | Windows  | 1.22       | 386          |
-| Windows  | 1.21       | 386          |
 
 While this project should work for other systems, no compatibility guarantees
 are made for those systems currently.