BUGFIX ci image to include go

cimg/go is a Docker image created by CircleCI with continuous integration builds in mind. Each tag contains a complete Go version and toolchain, the testing wrapper gotestsum, and any binaries and tools that are required for builds to complete successfully in a CircleCI environment.

Author: mattclegg

.circleci/config.yml

@@ -5,7 +5,7 @@ version: 2.1
 jobs:
   build:
     machine:
-      image: ubuntu-2004:202201-02
+      image: cimg/go:1.20
     environment:
       ENV: CI
       GO111MODULE: "on"
@@ -35,9 +35,6 @@ jobs:
           command: |
             mkdir -p /tmp/artifacts
             mkdir -p /tmp/test-results
-      - run: sudo rm -rf /usr/local/go
-      - run: wget https://golang.org/dl/go1.20.1.linux-amd64.tar.gz -O /tmp/go.tgz
-      - run: sudo tar -C /usr/local -xzf /tmp/go.tgz
       - run: go version
       - run: go get -v -t -d ./...
       - run: make lint