update ejs in 3.28.1 release for loopback #4350

Hi, @dhmlau @achrinza,

Issue Description

I noticed that a vulnerability is introduced in loopback@3.28.0:
Vulnerability SNYK-JS-EJS-1049328 affects package ejs (versions:<3.1.6): https://snyk.io/vuln/SNYK-JS-EJS-1049328
The above vulnerable package is referenced by loopback@3.28.0 via:
loopback@3.28.0 ➔ ejs@2.7.4

Since loopback@3.28.0 (9,351 downloads per week) is referenced by 75 downstream projects (e.g., loopback-workspace 5.3.0 (latest version), generator-loopback 6.4.0 (latest version), loopback-cli 5.2.0 (latest version), apiconnect-cli-loopback 5.0.0 (latest version), @loopback/booter-lb3app 2.4.2 (latest version)), the vulnerability SNYK-JS-EJS-1049328 can be propagated into these downstream projects and expose security threats to them via the following package dependency paths:
(1)@loopback/booter-lb3app@2.4.2 ➔ loopback@3.28.0 ➔ ejs@2.7.4
(2)apim-ui@5.21.28 ➔ loopback-workspace@4.6.0 ➔ loopback@3.28.0 ➔ ejs@2.7.4
......

If loopback@3.28.* removes the vulnerable package from the above version, then its fixed version can help downstream users decrease their pain.

Given the large number of downstream users, could you help update your package to remove the vulnerability from loopback@3.28.0 ?

Fixing suggestions

In loopback@3.28.1, maybe you can kindly try to perform the following upgrade :
ejs ^2.3.1 ➔ ^3.0.6;

Note:
ejs@3.1.6(>=3.1.6) has fixed the vulnerability SNYK-JS-EJS-1049328.

Thank you for your attention to this issue and welcome to share other ways to resolve the issue.

Best regards,
^_^