Ensure data entry exists for execution errors

According to the spec, the `data` entry should always exist once
execution starts. Only if an error is raised _before_ execution starts
should the `data` key be omitted.

The only test that needed updating was when an `ExecutionError` was
raised during the `execute_query` trace hook. Despite this running
before `super`, this still happens "during execution" and should have
the `data` key present.

Ref: https://spec.graphql.org/draft/#sec-Data

Author: swalkinshaw

lib/graphql/execution/interpreter.rb

@@ -80,7 +80,6 @@ def run_all(schema, query_options, context: {}, max_complexity: schema.max_compl
                       end
                     rescue GraphQL::ExecutionError => err
                       query.context.errors << err
-                      NO_OPERATION
                     end
                   end
                   results[idx] = result

spec/graphql/execution/instrumentation_spec.rb

@@ -128,8 +128,13 @@ def int(value:)
       it "rescues execution errors from execute_query" do
         context = {raise_execution_error: true}
         res = schema.execute(" { int(value: 2) } ", context: context)
-        assert_equal "Raised from trace execute_query", res["errors"].first["message"]
-        refute res.key?("data"), "The query doesn't run"
+
+        assert_equal({
+          "data" => nil,
+          "errors" => [
+            { "message" => "Raised from trace execute_query" },
+          ]
+        }, res.to_h)
       end
 
       it "can assign a query string there" do