Enable the LaTeX setting in Edit Site Information and you will be unable to add LTI tools.
This happens because the code which adds the lti tools to the site is modifying a copy of the site object, which never makes it back to the caller. Then, when the latex setup code runs, it is working on the original site object that wasn't modified, and commits that copy. This reverts the modifications made by the lti code.
Linked PR will move the latex setup into the same method that runs the lti setup. As a consequence of this move, the latex enabling code now runs during site creation (although it looks like only if you make the site unpublished). This should be fine because the enabling code will recognize that mathjax is not enabled for the new site and do nothing.