Update dependency golang-version to v1.21.4 (#991)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/docker.yaml

@@ -37,7 +37,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v4
         with:
-          go-version: 1.21.3
+          go-version: 1.21.4
 
       # set up the test environment
       - uses: cybozu/octoken-action@v1

.github/workflows/go.yaml

@@ -20,5 +20,5 @@ jobs:
   go:
     uses: int128/kubebuilder-workflows/.github/workflows/go.yaml@v1
     with:
-      go-version: 1.21.3
+      go-version: 1.21.4
       golangci-lint-version: v1.55.2