Handle thrown values correctly even if they are not instances of Error.

[ardatan]

Some libraries like undici throw objects that are not Error instances when the response is tried to parse as JSON but failed.
In that case, executor prints an error like below;

NonErrorThrown: Unexpected error value: {...}
at toError (/usr/src/app/node_modules/graphql/jsutils/toError.js:16:7)
at locatedError (/usr/src/app/node_modules/graphql/error/locatedError.js:20:46)
at /usr/src/app/node_modules/@graphql-tools/executor/cjs/execution/execute.js:330:58
at processTicksAndRejections (node:internal/process/task_queues:95:5)
at async /usr/src/app/node_modules/@graphql-tools/executor/cjs/execution/promiseForObject.js:18:35
at async Promise.all (index 0)