Update to LTI 1.3

[dgwn]

Materia is currently using an old version of the 1EdTech (formerly IMS Global) LTI spec. According to this schedule, "All support for LTI versions 1.0, 1.1, 1.1.1, 1.1.2, 1.2, and 2.0 will end on June 30, 2022", making 1.3 the de facto standard going forward. Per this community update from Canvas LMS, 1.3 is now the recommended version for new integrations and any integrations wishing to update their security framework.

At the time this issue is being opened, Canvas has not yet announced plans to stop support for the older versions of the spec. In 2019 a representative from Instructure, the developer of Canvas, stated

We haven't determined a deprecation schedule yet for our LTI v1.0 and v1.1 support in Canvas, but estimate it will be "many years" due to the number of tools using those standards in our ecosystem.

A subsequent update from the project manager for Canvas LTI endpoints in November 2022 stated:

Once we make a decision on a deprecation date for 1.1 we will give 12 months notice before we stop supporting 1.1 so that tools and schools have plenty of time to transition over. After that initial 12 months of support we anticipate another 12 months where the endpoints will still be available but not actively supported.

There does not seem to have been any official updates from Instructure beyond this point, indicating that there will be at least 24 months before deprecated tools may no longer work inside the LMS. It would be great to get ahead of this schedule (whenever dates are actually announced) in order to avoid racing the clock, as well as to take advantage of the security improvements and new features of LTI 1.3.

For more info on the features of LTI 1.3, see http://www.imsglobal.org/activity/learning-tools-interoperability-lti®