ep: Docker Bump golang from 1.20-alpine3.17 to 1.21-alpine3.17

Bumps golang from 1.20-alpine3.17 to 1.21-alpine3.17.

---
updated-dependencies:
- dependency-name: golang
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/main.yaml

@@ -21,7 +21,7 @@ jobs:
   test:
     name: test
     runs-on: ubuntu-latest
-    container: golang:1.20-alpine3.17
+    container: golang:1.21-alpine3.17
     steps:
     - name: Install git
       run: apk add --update --no-cache git
@@ -37,7 +37,7 @@ jobs:
   build:
     name: build
     runs-on: ubuntu-latest
-    container: golang:1.20-alpine3.17
+    container: golang:1.21-alpine3.17
     strategy:
       matrix:
         os: [linux, darwin, windows]
@@ -105,7 +105,10 @@ jobs:
           "kindest/node:v1.22.15",
           "kindest/node:v1.23.13",
           "kindest/node:v1.24.7",
-          "kindest/node:v1.25.3"
+          "kindest/node:v1.25.3",
+          "kindest/node:v1.26.6",
+          "kindest/node:v1.27.3",
+          "kindest/node:v1.28.0"
         ]
     steps:
     - name: Checkout

Dockerfile

@@ -1,4 +1,4 @@
-FROM --platform=$BUILDPLATFORM golang:1.20-alpine3.17 AS builder
+FROM --platform=$BUILDPLATFORM golang:1.21-alpine3.17 AS builder
 ARG GITHUB_REF GITHUB_SHA
 WORKDIR /src
 COPY go.mod go.sum ./

go.mod

@@ -1,6 +1,6 @@
 module github.com/doitintl/kube-no-trouble
 
-go 1.20
+go 1.18
 
 require (
 	github.com/ghodss/yaml v1.0.0