chore(deps): bump lodash

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.19 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.19...4.17.21)

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

Author: dependabot[bot]

scripts/docs.angularjs.org-firebase/functions/yarn.lock

@@ -1460,15 +1460,10 @@ lodash.once@^4.0.0:
   resolved "https://registry.yarnpkg.com/lodash.once/-/lodash.once-4.1.1.tgz#0dd3971213c7c56df880977d504c88fb471a97ac"
   integrity sha1-DdOXEhPHxW34gJd9UEyI+0cal6w=
 
-lodash@^4.17.14:
-  version "4.17.19"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.19.tgz#e48ddedbe30b3321783c5b4301fbd353bc1e4a4b"
-  integrity sha512-JNvd8XER9GQX0v2qJgsaN/mzFCNA5BRe/j8JN9d+tWyGLSodKQHKFicdwNYzWwI3wjRnaKPsGj1XkBjx/F96DQ==
-
-lodash@^4.17.20:
-  version "4.17.20"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.20.tgz#b44a9b6297bcb698f1c51a3545a2b3b368d59c52"
-  integrity sha512-PlhdFcillOINfeV7Ni6oF1TAEayyZBoZ8bcshTHqOYJYlrqzRK5hagpagky5o4HfCzzd1TRkXPMFq6cKk9rGmA==
+lodash@^4.17.14, lodash@^4.17.20:
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 long@^4.0.0:
   version "4.0.0"