TRIVIAL: Bump the gomod group with 2 updates

Bumps the gomod group with 2 updates: [go.uber.org/zap](https://github.com/uber-go/zap) and [k8s.io/kubectl](https://github.com/kubernetes/kubectl).


Updates `go.uber.org/zap` from 1.16.0 to 1.26.0
- [Release notes](https://github.com/uber-go/zap/releases)
- [Changelog](https://github.com/uber-go/zap/blob/master/CHANGELOG.md)
- [Commits](uber-go/zap@v1.16.0...v1.26.0)

Updates `k8s.io/kubectl` from 0.20.5 to 0.28.4
- [Commits](kubernetes/kubectl@v0.20.5...v0.28.4)

---
updated-dependencies:
- dependency-name: go.uber.org/zap
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: gomod
- dependency-name: k8s.io/kubectl
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: gomod
...

Signed-off-by: dependabot[bot] <[email protected]>

go.mod

@@ -3,9 +3,9 @@ module spot-termination-handler
 go 1.16
 
 require (
-	go.uber.org/zap v1.16.0
-	k8s.io/api v0.20.5
-	k8s.io/apimachinery v0.20.5
-	k8s.io/client-go v0.20.5
-	k8s.io/kubectl v0.20.5
+	go.uber.org/zap v1.26.0
+	k8s.io/api v0.28.4
+	k8s.io/apimachinery v0.28.4
+	k8s.io/client-go v0.28.4
+	k8s.io/kubectl v0.28.4
 )