change HTTP method to comply with spec

There is discrepancy with the spec, it has PUT

pageserver/client/src/mgmt_api.rs

@@ -432,7 +432,7 @@ impl Client {
             self.mgmt_api_endpoint
         );
 
-        self.request(Method::POST, &uri, req)
+        self.request(Method::PUT, &uri, req)
             .await?
             .json()
             .await

pageserver/src/http/routes.rs

@@ -2955,7 +2955,7 @@ pub fn make_router(
             "/v1/tenant/:tenant_shard_id/timeline/:timeline_id/preserve_initdb_archive",
             |r| api_handler(r, timeline_preserve_initdb_handler),
         )
-        .post(
+        .put(
             "/v1/tenant/:tenant_shard_id/timeline/:timeline_id/archival_config",
             |r| api_handler(r, timeline_archival_config_handler),
         )

storage_controller/src/http.rs

@@ -1849,7 +1849,7 @@ pub fn make_router(
                 RequestName("v1_tenant_timeline"),
             )
         })
-        .post(
+        .put(
             "/v1/tenant/:tenant_id/timeline/:timeline_id/archival_config",
             |r| {
                 tenant_service_handler(

storage_controller/src/pageserver_client.rs

@@ -238,7 +238,7 @@ impl PageserverClient {
     ) -> Result<()> {
         measured_request!(
             "timeline_archival_config",
-            crate::metrics::Method::Post,
+            crate::metrics::Method::Put,
             &self.node_id_label,
             self.inner
                 .timeline_archival_config(tenant_shard_id, timeline_id, req)

test_runner/fixtures/pageserver/http.py

@@ -631,7 +631,7 @@ def timeline_archival_config(
         log.info(
             f"requesting timeline archival config {config} for tenant {tenant_id} and timeline {timeline_id}"
         )
-        res = self.post(
+        res = self.put(
             f"http://localhost:{self.port}/v1/tenant/{tenant_id}/timeline/{timeline_id}/archival_config",
             json=config,
         )