Bump lodash from 4.17.15 to 4.17.21 in /tfjs-vis/demos/api (#6228)

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.15 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.15...4.17.21)

---
updated-dependencies:
- dependency-name: lodash
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

tfjs-vis/demos/api/yarn.lock

@@ -3961,9 +3961,9 @@ lodash.uniq@^4.5.0:
   integrity sha1-0CJTc662Uq3BvILklFM5qEJ1R3M=
 
 lodash@^4.17.11, lodash@^4.17.13, lodash@^4.17.15, lodash@^4.17.4:
-  version "4.17.15"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"
-  integrity sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 log-symbols@^2.2.0:
   version "2.2.0"