Bump handlebars from 4.0.12 to 4.2.1

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.0.12 to 4.2.1.
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/wycats/handlebars.js/blob/v4.2.1/release-notes.md)
- [Commits](handlebars-lang/handlebars.js@v4.0.12...v4.2.1)

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

Author: dependabot[bot]

yarn.lock

@@ -3461,9 +3461,9 @@ handle-thing@^1.2.5:
   integrity sha1-/Xqtcmvxpf0W38KbL3pmAdJxOcQ=
 
 handlebars@^4.0.12:
-  version "4.2.0"
-  resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.2.0.tgz#57ce8d2175b9bbb3d8b3cf3e4217b1aec8ddcb2e"
-  integrity sha512-Kb4xn5Qh1cxAKvQnzNWZ512DhABzyFNmsaJf3OAkWNa4NkaqWcNI8Tao8Tasi0/F4JD9oyG0YxuFyvyR57d+Gw==
+  version "4.2.1"
+  resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.2.1.tgz#dc69c0e61604224f0c23b38b5b6741db210b57da"
+  integrity sha512-bqPIlDk06UWbVEIFoYj+LVo42WhK96J+b25l7hbFDpxrOXMphFM3fNIm+cluwg4Pk2jiLjWU5nHQY7igGE75NQ==
   dependencies:
     neo-async "^2.6.0"
     optimist "^0.6.1"