use yarn installed katex

debian/patches/0420-use-system-libs.patch

@@ -1,6 +1,6 @@
 --- a/package.json
 +++ b/package.json
-@@ -13,58 +13,31 @@
+@@ -13,58 +13,32 @@
      "webpack-prod": "NODE_ENV=production webpack --config config/webpack.config.js"
    },
    "dependencies": {
@@ -47,7 +47,7 @@
 -    "js-cookie": "^2.1.3",
 -    "jszip": "^3.1.3",
 -    "jszip-utils": "^0.0.2",
--    "katex": "^0.8.3",
+     "katex": "^0.8.3",
 -    "marked": "^0.3.12",
      "monaco-editor": "0.10.0",
 -    "mousetrap": "^1.4.6",
@@ -60,7 +60,7 @@
      "react-dev-utils": "^0.5.2",
      "sanitize-html": "^1.16.1",
      "select2": "3.5.2-browserify",
-@@ -75,8 +48,6 @@
+@@ -75,8 +49,6 @@
      "three-orbit-controls": "^82.1.0",
      "three-stl-loader": "^1.0.4",
      "timeago.js": "^3.0.2",
@@ -69,7 +69,7 @@
      "visibilityjs": "^1.2.4",
      "vue": "^2.5.13",
      "vue-loader": "^13.7.0",
-@@ -84,36 +55,9 @@
+@@ -84,36 +56,9 @@
      "vue-router": "^3.0.1",
      "vue-template-compiler": "^2.5.13",
      "vuex": "^3.0.1",