fix(blooms): Fix panic in bloom gateway (#13303)

The slice of block queriers can contain `nil` values, which causes nip pointer dereference when calling `Close()` on them.

Signed-off-by: Christian Haudum <christian.haudum@gmail.com>

pkg/bloomgateway/processor.go

@@ -119,7 +119,7 @@ func (p *processor) processBlocks(ctx context.Context, bqs []*bloomshipper.Close
 	hasClosed := make([]bool, len(bqs))
 	defer func() {
 		for i, bq := range bqs {
-			if !hasClosed[i] {
+			if bq != nil && !hasClosed[i] {
 				_ = bq.Close()
 			}
 		}