Merge pull request containerd#10176 from akhilerm/remove-go-1.21

remove go1.21.9 from CI matrix

Author: Maksym Pavlenko

.github/workflows/ci.yml

@@ -191,7 +191,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-22.04, actuated-arm64-4cpu-16gb, macos-12, windows-2019, windows-2022]
-        go-version: ["1.21.9", "1.22.2"]
+        go-version: ["1.22.2"]
         exclude:
           - os: ${{ github.repository != 'containerd/containerd' && 'actuated-arm64-4cpu-16gb' }}
     steps: