chore: fixate terraform provider versions, make them handleable by renovate

terraform/common/init.tf

 terraform {
+  # allow the lowest common version across all projects, so that the current CI docker image version suits all projects
+  required_version = ">= 1.9"
+  required_providers {
+    google = {
+      source  = "hashicorp/google"
+      version = "6.21.0"
+    }
+    google-beta = {
+      source  = "hashicorp/google-beta"
+      version = "6.21.0"
+    }
+  }
   backend "gcs" {
     bucket = "holi-shared-terraform-state"
     prefix = "donations-api-common"

terraform/environments/init.tf

 terraform {
+  # allow the lowest common version across all projects, so that the current CI docker image version suits all projects
+  required_version = ">= 1.9"
+  required_providers {
+    google = {
+      source  = "hashicorp/google"
+      version = "6.21.0"
+    }
+    google-beta = {
+      source  = "hashicorp/google-beta"
+      version = "6.21.0"
+    }
+  }
   backend "gcs" {
     bucket = "holi-shared-terraform-state"
     prefix = "donations-api-environments"