feat: add pre-commit check in ci

- add a ci workflow to verify pre-commit passes
- fix pre-commit errors/warnings:
  - missing required_version
  - missing required_providers
  - fixed terraform_deprecated_interpolation
  - removed terraform_unused_declarations

modules/vault_cluster/.tflint.hcl

@@ -1,11 +0,0 @@
-rule "terraform_required_providers" {
-  enabled = false
-}
-
-rule "terraform_required_version" {
-  enabled = false
-}
-
-rule "terraform_unused_declarations" {
-  enabled = false
-}