Bump lodash from 4.17.20 to 4.17.21 in /packages/labextension

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.20 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.20...4.17.21)

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

Author: dependabot[bot]

packages/labextension/yarn.lock

@@ -2344,9 +2344,9 @@ lodash.escape@^4.0.1:
   integrity sha1-yQRGkMIeBClL6qUXcS/e0fqI3pg=
 
 lodash@^4.17.14, lodash@^4.17.15, lodash@^4.17.19, lodash@^4.17.4:
-  version "4.17.20"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.20.tgz#b44a9b6297bcb698f1c51a3545a2b3b368d59c52"
-  integrity sha512-PlhdFcillOINfeV7Ni6oF1TAEayyZBoZ8bcshTHqOYJYlrqzRK5hagpagky5o4HfCzzd1TRkXPMFq6cKk9rGmA==
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 loose-envify@^1.0.0, loose-envify@^1.1.0, loose-envify@^1.4.0:
   version "1.4.0"