Bump @material-ui/icons from 4.9.1 to 4.11.2 in /web/app

Bumps [@material-ui/icons](https://github.com/mui-org/material-ui/tree/HEAD/packages/material-ui-icons) from 4.9.1 to 4.11.2.
- [Release notes](https://github.com/mui-org/material-ui/releases)
- [Changelog](https://github.com/mui-org/material-ui/blob/v4.11.2/CHANGELOG.md)
- [Commits](https://github.com/mui-org/material-ui/commits/v4.11.2/packages/material-ui-icons)

---
updated-dependencies:
- dependency-name: "@material-ui/icons"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

web/app/package.json

@@ -12,7 +12,7 @@
     "@lingui/macro": "2.9.2",
     "@lingui/react": "2.9.2",
     "@material-ui/core": "4.11.4",
-    "@material-ui/icons": "4.9.1",
+    "@material-ui/icons": "4.11.2",
     "@material-ui/lab": "^4.0.0-alpha.58",
     "classnames": "2.2.6",
     "css-mediaquery": "^0.1.2",

web/app/yarn.lock

@@ -1368,10 +1368,10 @@
     react-is "^16.8.0 || ^17.0.0"
     react-transition-group "^4.4.0"
 
-"@material-ui/icons@4.9.1":
-  version "4.9.1"
-  resolved "https://registry.yarnpkg.com/@material-ui/icons/-/icons-4.9.1.tgz#fdeadf8cb3d89208945b33dbc50c7c616d0bd665"
-  integrity sha512-GBitL3oBWO0hzBhvA9KxqcowRUsA0qzwKkURyC8nppnC3fw54KPKZ+d4V1Eeg/UnDRSzDaI9nGCdel/eh9AQMg==
+"@material-ui/icons@4.11.2":
+  version "4.11.2"
+  resolved "https://registry.yarnpkg.com/@material-ui/icons/-/icons-4.11.2.tgz#b3a7353266519cd743b6461ae9fdfcb1b25eb4c5"
+  integrity sha512-fQNsKX2TxBmqIGJCSi3tGTO/gZ+eJgWmMJkgDiOfyNaunNaxcklJQFaFogYcFl0qFuaEz1qaXYXboa/bUXVSOQ==
   dependencies:
     "@babel/runtime" "^7.4.4"