I have written the below class. However when I schedule the class I get error 'Callout from scheduled Apex not supported'. Can some tell me how to get it working?

global class Accenture_Current_Backlog implements System.Schedulable {

    global void execute(SchedulableContext sc) {
        ApexPages.PageReference report = new ApexPages.PageReference('/00O1a0000039OPy?csv=1');
        Messaging.EmailFileAttachment attachment = new Messaging.EmailFileAttachment();
        attachment.setFileName('Accenture_Current_Backlog.csv');
        attachment.setBody(report.getContent());
        attachment.setContentType('text/csv');
        Messaging.SingleEmailMessage message = new Messaging.SingleEmailMessage();
        message.setFileAttachments(new Messaging.EmailFileAttachment[] { attachment } );
        message.setSubject('Accenture Current Backlog Report');
        message.setPlainTextBody('The report is attached.');
        message.setToAddresses( new String[] { 'abhijit.bhagwat@live.in','abhijit.bhagwat@yahoo.in' } );
        message.setCcAddresses(new String[] { 'atedbshsgt2asgwat@qualys.com.com'});
        Messaging.sendEmail( new Messaging.SingleEmailMessage[] { message } );
        
    }
    }