Merge pull request #25205 from overleaf/mj-subeqnarray

[web] Add subeqnarray support

GitOrigin-RevId: a26fe362ec6e053134f9f4454979b773cae33241

services/web/frontend/js/features/source-editor/lezer-latex/tokens.mjs

@@ -696,6 +696,8 @@ const equationArrayEnvNames = new Set([
   'rcases*',
   'IEEEeqnarray',
   'IEEEeqnarray*',
+  'subeqnarray',
+  'subeqnarray*',
 ])
 
 const verbatimEnvNames = new Set([