Replace content of cve-to-wso2-security-advisory-mapping to say this is discontinued

[ayomawdb]

Please change the contents of the following file to say that this page is discounted and relevant information is now available in each advisory page. For example check: https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2022/WSO2-2022-1698/

https://security.docs.wso2.com/en/latest/security-announcements/cve-to-wso2-security-advisory-mapping/