Hii,

Odoo routes returning JSON should set type='json' or return a Response object (not just a dictionary).

Also, you are using type='http' but returning a plain Python dictionary. For JSON responses, it's better to either:

• Use type='json' (automatic JSON serialization)
• Or manually return a Response with headers

here is updated code 
# -*- coding: utf-8 -*-

from odoo import http

from odoo.http import request

import json

class StudentController(http.Controller):

    @http.route('/school/schoolrecords', type='json', auth='public', methods=['GET'])

    def get_school_records(self):

        school_rec = request.env['school.student'].sudo().search([])

        school = []

        for rec in school_rec:

            school.append({

                'id': controllers.py

i hope it is use full