Update @khanacademy/mathjax-renderer peer dep to 3.0.0 (#2522)

## Summary:
This silences some warnings about incorrect peer deps when installing packages
in webapp. The choice of 2.1.1 vs. 3.0.0 isn't relevant for Perseus (we don't
use any of the changed APIs) so perhaps we could have used a version range like
`2.1.1 - 3`. However, that is not necessarily forward-compatible, since Perseus
might someday add features that depend on 3.x.x-only APIs. Dependency
management is hard.

Issue: none

## Test plan:

CI should pass.

Author: benchristel

Reviewers: jeremywiebe, handeyeco

Required Reviewers:

Approved By: jeremywiebe

Checks: ✅ 8 checks were successful

Pull Request URL: #2522

Author: benchristel

.changeset/long-dolls-run.md

@@ -0,0 +1,9 @@
+---
+"@khanacademy/math-input": major
+"@khanacademy/perseus-editor": major
+---
+
+Breaking change: version `^3.0.0` of `@khanacademy/mathjax-renderer` is now
+required as a peer dep, instead of `^2.1.1`. Clients should update
+`@khanacademy/mathjax-renderer` at their convenience; nothing will immediately
+break if you stay on 2.x.x for now.

pnpm-workspace.yaml

@@ -13,7 +13,7 @@ catalog:
     tiny-invariant: ^1.3.1
     underscore: ^1.4.4
     vite: 5.1.0
-    "@khanacademy/mathjax-renderer": ^2.1.1
+    "@khanacademy/mathjax-renderer": ^3.0.0
     "@khanacademy/wonder-blocks-accordion": 3.1.14
     "@khanacademy/wonder-blocks-banner": 4.1.16
     "@khanacademy/wonder-blocks-button": 10.0.1