remove removed Debug/getDebugChainHeads V1 (#4970)

* remove removed Debug/getDebugChainHeads V1

* REST API tests

beacon_chain/rpc/rest_debug_api.nim

@@ -61,13 +61,6 @@ proc installDebugApiHandlers*(router: var RestRouter, node: BeaconNode) =
           RestApiResponse.jsonError(Http500, InvalidAcceptError)
     return RestApiResponse.jsonError(Http404, StateNotFoundError)
 
-  # https://ethereum.github.io/beacon-APIs/#/Debug/getDebugChainHeads
-  router.api(MethodGet,
-             "/eth/v1/debug/beacon/heads") do () -> RestApiResponse:
-    return RestApiResponse.jsonResponse(
-      node.dag.heads.mapIt((root: it.root, slot: it.slot))
-    )
-
   # https://ethereum.github.io/beacon-APIs/#/Debug/getDebugChainHeadsV2
   router.api(MethodGet,
              "/eth/v2/debug/beacon/heads") do () -> RestApiResponse:

beacon_chain/spec/eth2_apis/rest_debug_calls.nim

@@ -13,11 +13,6 @@ import
 
 export chronos, client, rest_types, eth2_rest_serialization
 
-proc getDebugChainHeads*(): RestResponse[GetDebugChainHeadsResponse] {.
-     rest, endpoint: "/eth/v1/debug/beacon/heads",
-     meth: MethodGet.}
-  ## https://ethereum.github.io/beacon-APIs/#/Beacon/getDebugChainHeads
-
 proc getStateV2Plain*(state_id: StateIdent): RestPlainResponse {.
      rest, endpoint: "/eth/v2/debug/beacon/states/{state_id}",
      accept: preferSSZ,

docs/the_nimbus_book/src/api.md

@@ -466,14 +466,6 @@ Equivalent call in the official REST API:
 curl http://localhost:5052/eth/v2/debug/beacon/states/head -s | jq
 ```
 
-### [`get_v1_debug_beacon_heads`](https://ethereum.github.io/eth2.0-APIs/#/Debug/getDebugChainHeads)
-
-Equivalent call in the official REST API:
-
-```
-curl http://localhost:5052/eth/v1/debug/beacon/heads -s | jq
-```
-
 ## Nimbus extensions
 
 ### getBeaconHead

ncli/resttest-rules.json

@@ -2817,18 +2817,6 @@
       "body": [{"operator": "jstructcmps", "start": ["data"], "value": {"chain_id": "", "address": ""}}]
     }
   },
-  {
-    "topics": ["debug"],
-    "request": {
-      "url": "/eth/v1/debug/beacon/heads",
-      "headers": {"Accept": "application/json"}
-    },
-    "response": {
-      "status": {"operator": "equals", "value": "200"},
-      "headers": [{"key": "Content-Type", "value": "application/json", "operator": "equals"}],
-      "body": [{"operator": "jstructcmps", "start": ["data"], "value": [{"root": "", "slot": ""}]}]
-    }
-  },
   {
     "topics": ["debug", "beacon_states_head_slow", "slow"],
     "request": {