Use node-katex from system

debian/patches/nodejs/0070-use-system-katex.patch

@@ -0,0 +1,11 @@
+--- a/package.json
++++ b/package.json
+@@ -141,7 +141,7 @@
+     "js-cookie": "^3.0.0",
+     "js-yaml": "^3.13.1",
+     "jszip": "^3.1.3",
+-    "katex": "^0.13.2",
++    "katex": "link:/usr/share/nodejs/katex",
+     "lodash": "^4.17.20",
+     "lowlight": "^2.6.1",
+     "marked": "^4.0.18",

debian/patches/series

@@ -18,6 +18,7 @@ nodejs/0030-use-yarnpkg.patch
 nodejs/0040-use-packaged-modules.patch
 nodejs/0050-add-babel-plugins.patch
 nodejs/0060-use-system-yaml.patch
+nodejs/0070-use-system-katex.patch
 tweaks/0010-source-init-functions.patch
 tweaks/0020-fix-mail-room-path.patch
 tweaks/0030-fix-gitlab-yml-path.patch