Remove done ephemeral shards (#7212)

What changed?
We now remove ephemeral shards that are reported done by the executors

Why?
This will allow executors to signal that an ephemeral shard should be removed when it's not needed any longer.

How did you test it?
Unit tests

Potential risks

Release notes

Documentation Changes

Author: jakobht

.gen/proto/sharddistributor/v1/executor.pb.go

@@ -155,6 +155,8 @@ func ToShardDistributorExecutorHeartbeatRequest(t *sharddistributorv1.HeartbeatR
 				status = types.ShardStatusINVALID
 			case sharddistributorv1.ShardStatus_SHARD_STATUS_READY:
 				status = types.ShardStatusREADY
+			case sharddistributorv1.ShardStatus_SHARD_STATUS_DONE:
+				status = types.ShardStatusDONE
 			}
 
 			shardStatusReports[shardKey] = &types.ShardStatusReport{

.gen/proto/sharddistributor/v1/executor.pb.yarpc.go

@@ -152,13 +152,14 @@ func (v *ShardStatusReport) GetShardLoad() (o float64) {
 	return
 }
 
-// ShardStatus is ppersisted to the DB with a string value mapping.
+// ShardStatus is persisted to the DB with a string value mapping.
 // Beware - if we want to change the name - it should be backward compatible and should be done in two steps.
 type ShardStatus int32
 
 const (
 	ShardStatusINVALID ShardStatus = 0
 	ShardStatusREADY   ShardStatus = 1
+	ShardStatusDONE    ShardStatus = 2
 )
 
 type ExecutorHeartbeatResponse struct {

common/types/mapper/proto/sharddistributor.go

@@ -57,6 +57,7 @@ message ShardStatusReport {
 enum ShardStatus {
   SHARD_STATUS_INVALID = 0;
   SHARD_STATUS_READY = 1;
+  SHARD_STATUS_DONE = 2;
 }