Enable go 1.21.0 in the CI build (#998)

Signed-off-by: Cosmin Cojocar <gcojocar@adobe.com>

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
   test:
     strategy:
       matrix:
-        version: [{go: '1.19.12', golangci: 'v1.52.0'}, {go: '1.20.7', golangci: 'latest'}]
+        version: [{go: '1.19.12', golangci: 'v1.52.0'}, {go: '1.20.7', golangci: 'latest'}, {go: '1.21.0', golangci: 'latest'}]
     runs-on: ubuntu-latest
     env:
       GO111MODULE: on
@@ -46,7 +46,7 @@ jobs:
       - name: Setup go
         uses: actions/setup-go@v4
         with:
-          go-version: '1.20.7'
+          go-version: '1.21.0'
       - name: Checkout Source 
         uses: actions/checkout@v3
       - uses: actions/cache@v3

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: '1.20.7'
+          go-version: '1.21.0'
       - name: Install Cosign
         uses: sigstore/cosign-installer@v3
         with:
@@ -66,7 +66,7 @@ jobs:
           tags: ${{steps.meta.outputs.tags}}
           labels: ${{steps.meta.outputs.labels}}
           push: true
-          build-args: GO_VERSION=1.20
+          build-args: GO_VERSION=1.21
       - name: Sign Docker Image
         run: cosign sign --yes --key /tmp/cosign.key ${DIGEST}
         env: