Alerting: Support deleting rule groups in the provisioning API (#83514)

* Alerting: feat: support deleting rule groups in the provisioning API

Adds support for DELETE to the provisioning API's alert rule groups route, which allows deleting the rule group with a
single API call. Previously, groups were deleted by deleting rules one-by-one.

Fixes #81860

This change doesn't add any new paths to the API, only new methods.

---------

Co-authored-by: Yuri Tseretyan <yuriy.tseretyan@grafana.com>

pkg/services/ngalert/api/tooling/api.json

@@ -5962,6 +5962,44 @@
    }
   },
   "/v1/provisioning/folder/{FolderUID}/rule-groups/{Group}": {
+   "delete": {
+    "description": "Delete rule group",
+    "operationId": "RouteDeleteAlertRuleGroup",
+    "parameters": [
+     {
+      "in": "path",
+      "name": "FolderUID",
+      "required": true,
+      "type": "string"
+     },
+     {
+      "in": "path",
+      "name": "Group",
+      "required": true,
+      "type": "string"
+     }
+    ],
+    "responses": {
+     "204": {
+      "description": " The alert rule group was deleted successfully."
+     },
+     "403": {
+      "description": "ForbiddenError",
+      "schema": {
+       "$ref": "#/definitions/ForbiddenError"
+      }
+     },
+     "404": {
+      "description": "NotFound",
+      "schema": {
+       "$ref": "#/definitions/NotFound"
+      }
+     }
+    },
+    "tags": [
+     "provisioning"
+    ]
+   },
    "get": {
     "operationId": "RouteGetAlertRuleGroup",
     "parameters": [