chore(deps): bump lodash-es in /examples/gatsby/custom-config (#949)

Bumps [lodash-es](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-es
  dependency-type: indirect
...

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

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

examples/gatsby/custom-config/yarn.lock

@@ -9390,9 +9390,9 @@ lockfile@^1.0.4:
     signal-exit "^3.0.2"
 
 lodash-es@^4.17.11, lodash-es@^4.17.14:
-  version "4.17.15"
-  resolved "https://registry.yarnpkg.com/lodash-es/-/lodash-es-4.17.15.tgz#21bd96839354412f23d7a10340e5eac6ee455d78"
-  integrity sha512-rlrc3yU3+JNOpZ9zj5pQtxnx2THmvRykwL4Xlxoa8I9lHBlVbbyPhgyPMioxVZ4NqyxaVVtaJnzsyOidQIhyyQ==
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash-es/-/lodash-es-4.17.21.tgz#43e626c46e6591b7750beb2b50117390c609e3ee"
+  integrity sha512-mKnC+QJ9pWVzv+C4/U3rRsHapFfHvQFoFB92e52xeyGMcX6/OlIl78je1u8vePzYZSkkogMPJ2yjxxsb89cxyw==
 
 lodash._reinterpolate@^3.0.0:
   version "3.0.0"