fix(proto): format proto file with buf format

- Add blank line after package declaration
- Add newline at end of file

This fixes the buf format CI check.

Author: whywaita

api/proto/myshoes.proto

@@ -1,6 +1,7 @@
 syntax = "proto3";
 
 package whywaita.myshoes;
+
 option go_package = "github.com/whywaita/myshoes/api/proto.go";
 
 service Shoes {
@@ -40,4 +41,4 @@ message DeleteInstanceRequest {
   repeated string labels = 2;
 }
 
-message DeleteInstanceResponse {}
+message DeleteInstanceResponse {}