dependencies: Upgrade JavaScript dependencies.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

package.json

@@ -14,7 +14,7 @@
     "@uppy/core": "^1.7.1",
     "@uppy/progress-bar": "^1.3.4",
     "@uppy/xhr-upload": "^1.4.2",
-    "autoprefixer": "^9.6.1",
+    "autoprefixer": "^10.0.0",
     "autosize": "^4.0.2",
     "babel-loader": "^8.0.6",
     "blueimp-md5": "^2.10.0",
@@ -22,7 +22,7 @@
     "clean-css": "^4.2.1",
     "clipboard": "^2.0.4",
     "core-js": "^3.0.1",
-    "css-loader": "^3.2.0",
+    "css-loader": "^4.3.0",
     "emoji-datasource-google": "^5.0.1",
     "emoji-datasource-google-blob": "npm:emoji-datasource-google@^3.0.0",
     "emoji-datasource-twitter": "^5.0.1",
@@ -46,11 +46,12 @@
     "moment-timezone": "^0.5.25",
     "optimize-css-assets-webpack-plugin": "^5.0.3",
     "plotly.js": "^1.48.1",
+    "postcss": "^8.0.3",
     "postcss-calc": "^7.0.1",
     "postcss-extend-rule": "^3.0.0",
-    "postcss-loader": "^3.0.0",
+    "postcss-loader": "^4.0.2",
-    "postcss-nested": "^4.1.2",
+    "postcss-nested": "^5.0.0",
-    "postcss-simple-vars": "^5.0.2",
+    "postcss-simple-vars": "^6.0.0",
     "regenerator-runtime": "^0.13.3",
     "script-loader": "^0.7.2",
     "shebang-loader": "^0.0.1",
@@ -64,7 +65,7 @@
     "terser-webpack-plugin": "^4.1.0",
     "turndown": "^6.0.0",
     "unorm": "^1.6.0",
-    "webfonts-loader": "^5.0.0",
+    "webfonts-loader": "^6.0.2",
     "webpack": "^4.33.0",
     "webpack-cli": "^3.3.2",
     "webpack4-bundle-tracker": "^0.0.1-beta",

version.py

@@ -44,4 +44,4 @@ API_FEATURE_LEVEL = 32
 #   historical commits sharing the same major version, in which case a
 #   minor version bump suffices.
 
-PROVISION_VERSION = '105.0'
+PROVISION_VERSION = '106.0'