ci: drop Terragrunt-specific no-direct-go-getter depguard rule (#1839)

This depguard rule was carried over from Terragrunt's golangci config. It
denies direct github.com/hashicorp/go-getter imports and points to
github.com/gruntwork-io/terragrunt/internal/getter as the replacement, but
Terratest is a separate Go module and cannot import another module's
internal package. Its carve-out paths (internal/getter, internal/util,
internal/cas) do not exist here either.

Terratest uses go-getter directly in modules/opa, so the rule fails lint on
every PR with no valid fix. Removing the rule (and depguard, which had no
other rules configured).

Author: james00012

.golangci.yml

@@ -18,7 +18,6 @@ linters:
     - bidichk
     - bodyclose
     - contextcheck
-    - depguard
     - dupl
     - durationcheck
     - errchkjson
@@ -60,30 +59,6 @@ linters:
     - wsl_v5
     - zerologlint
   settings:
-    depguard:
-      rules:
-        no-direct-go-getter:
-          # Direct hashicorp/go-getter imports are confined to the internal/getter
-          # package (which owns the integration) plus two carve-out files that
-          # would otherwise create import cycles. Everything else must go through
-          # internal/getter.
-          list-mode: lax
-          files:
-            - $all
-            - "!**/internal/getter/**"
-            - "!**/internal/util/file.go"
-            - "!**/internal/cas/stacks.go"
-          deny:
-            - pkg: github.com/hashicorp/go-getter
-              desc: use github.com/gruntwork-io/terragrunt/internal/getter instead
-            - pkg: github.com/hashicorp/go-getter/v2
-              desc: use github.com/gruntwork-io/terragrunt/internal/getter instead
-            - pkg: github.com/hashicorp/go-getter/v2/helper/url
-              desc: use github.com/gruntwork-io/terragrunt/internal/getter URLParse instead
-            - pkg: github.com/hashicorp/go-getter/s3/v2
-              desc: use github.com/gruntwork-io/terragrunt/internal/getter instead
-            - pkg: github.com/hashicorp/go-getter/gcs/v2
-              desc: use github.com/gruntwork-io/terragrunt/internal/getter instead
     dupl:
       threshold: 120
     errcheck: