fix(seer): Align project grouping record deletion with Seer API (#111756)

Issue:
https://sentry.sentry.io/issues/5865067343/?project=1&query=is%3Aunresolved&referrer=issue-stream&statsPeriod=7d
This PR addresses the `seer.delete_grouping_records.project.failure`
errors, which saw a significant spike recently.

The root cause was a mismatch in how Sentry was calling the Seer API
endpoint for deleting grouping records by project
(`/v0/issues/similar-issues/grouping-record/delete`).

Specifically, two issues were identified:
1. **Incorrect HTTP Method**: Sentry was sending a `POST` request, while
the Seer endpoint was defined as a `GET`.
2. **Incorrect Parameter Location**: Sentry was sending the `project_id`
in the request body, but Seer expected it as a **path parameter** (e.g.,
`/v0/issues/similar-issues/grouping-record/delete/{project_id}`).

This change updates the
`make_delete_grouping_records_by_project_request` function in
`src/sentry/seer/signed_seer_api.py` to:
*   Use the `GET` HTTP method.
* Construct the URL with the `project_id` included as a path parameter.
*   Send an empty body, as `GET` requests typically do not carry a body.

This fix ensures that Sentry correctly communicates with the Seer
service for project grouping record deletions, resolving the 404 errors
and allowing these background tasks to complete successfully.

Co-authored-by: sentry[bot] <39604003+sentry[bot]@users.noreply.github.com>

Author: sentry[bot]

src/sentry/seer/signed_seer_api.py

@@ -537,10 +537,12 @@ def make_delete_grouping_records_by_project_request(
     timeout: int | float | None = None,
     viewer_context: SeerViewerContext | None = None,
 ) -> BaseHTTPResponse:
+    project_id = body["project_id"]
     return make_signed_seer_api_request(
         seer_grouping_default_connection_pool,
-        "/v0/issues/similar-issues/grouping-record/delete",
-        body=orjson.dumps(body),
+        f"/v0/issues/similar-issues/grouping-record/delete/{project_id}",
+        body=b"",
+        method="GET",
         timeout=timeout,
         viewer_context=viewer_context,
     )