Bump the terraform group across 2 directories with 1 update (#1365)

Bumps the terraform group with 1 update in the /terraform/gcp/modules/argocd directory: [gavinbunney/kubectl](https://github.com/gavinbunney/terraform-provider-kubectl).
Bumps the terraform group with 1 update in the /terraform/gcp/modules/external_secrets directory: [gavinbunney/kubectl](https://github.com/gavinbunney/terraform-provider-kubectl).


Updates `gavinbunney/kubectl` from 1.14.0 to 1.16.0
- [Release notes](https://github.com/gavinbunney/terraform-provider-kubectl/releases)
- [Changelog](https://github.com/gavinbunney/terraform-provider-kubectl/blob/master/.goreleaser.yml)
- [Commits](gavinbunney/terraform-provider-kubectl@v1.14.0...v1.16.0)

Updates `gavinbunney/kubectl` from 1.14.0 to 1.16.0
- [Release notes](https://github.com/gavinbunney/terraform-provider-kubectl/releases)
- [Changelog](https://github.com/gavinbunney/terraform-provider-kubectl/blob/master/.goreleaser.yml)
- [Commits](gavinbunney/terraform-provider-kubectl@v1.14.0...v1.16.0)

---
updated-dependencies:
- dependency-name: gavinbunney/kubectl
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: terraform
- dependency-name: gavinbunney/kubectl
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: terraform
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

terraform/gcp/modules/argocd/versions.tf

@@ -20,7 +20,7 @@ terraform {
   required_providers {
     kubectl = {
       source  = "gavinbunney/kubectl"
-      version = "1.14.0"
+      version = "1.16.0"
     }
     helm = {
       source  = "hashicorp/helm"

terraform/gcp/modules/external_secrets/versions.tf

@@ -24,7 +24,7 @@ terraform {
     }
     kubectl = {
       source  = "gavinbunney/kubectl"
-      version = "1.14.0"
+      version = "1.16.0"
     }
     helm = {
       source  = "hashicorp/helm"