Build(deps): Bump async in /Resources/Private/FlatNav

Bumps [async](https://github.com/caolan/async) from 2.6.1 to 2.6.4.
- [Release notes](https://github.com/caolan/async/releases)
- [Changelog](https://github.com/caolan/async/blob/v2.6.4/CHANGELOG.md)
- [Commits](caolan/async@v2.6.1...v2.6.4)

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

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

Author: dependabot[bot]

Resources/Private/FlatNav/yarn.lock

@@ -414,10 +414,11 @@ async-each@^1.0.0:
   resolved "https://registry.yarnpkg.com/async-each/-/async-each-1.0.1.tgz#19d386a1d9edc6e7c1c85d388aedbcc56d33602d"
 
 async@^2.1.2, async@^2.4.1:
-  version "2.6.1"
-  resolved "https://registry.yarnpkg.com/async/-/async-2.6.1.tgz#b245a23ca71930044ec53fa46aa00a3e87c6a610"
+  version "2.6.4"
+  resolved "https://registry.yarnpkg.com/async/-/async-2.6.4.tgz#706b7ff6084664cd7eae713f6f965433b5504221"
+  integrity sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==
   dependencies:
-    lodash "^4.17.10"
+    lodash "^4.17.14"
 
 atob@^2.1.1:
   version "2.1.2"
@@ -3602,10 +3603,10 @@ lodash.upperfirst@^4.3.1:
   version "4.3.1"
   resolved "https://registry.yarnpkg.com/lodash.upperfirst/-/lodash.upperfirst-4.3.1.tgz#1365edf431480481ef0d1c68957a5ed99d49f7ce"
 
-lodash@^4.17.10, lodash@^4.17.4, lodash@^4.17.5:
-  version "4.17.19"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.19.tgz#e48ddedbe30b3321783c5b4301fbd353bc1e4a4b"
-  integrity sha512-JNvd8XER9GQX0v2qJgsaN/mzFCNA5BRe/j8JN9d+tWyGLSodKQHKFicdwNYzWwI3wjRnaKPsGj1XkBjx/F96DQ==
+lodash@^4.17.10, lodash@^4.17.14, lodash@^4.17.4, lodash@^4.17.5:
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 log-symbols@^2.0.0:
   version "2.2.0"