Bump sha.js from 2.4.11 to 2.4.12 in /example (#577)

Bumps [sha.js](https://github.com/crypto-browserify/sha.js) from 2.4.11 to 2.4.12.
- [Changelog](https://github.com/browserify/sha.js/blob/master/CHANGELOG.md)
- [Commits](browserify/sha.js@v2.4.11...v2.4.12)

---
updated-dependencies:
- dependency-name: sha.js
  dependency-version: 2.4.12
  dependency-type: indirect
...

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

Author: dependabot[bot]

example/yarn.lock

@@ -3980,15 +3980,7 @@ setprototypeof@1.2.0:
   resolved "https://registry.yarnpkg.com/setprototypeof/-/setprototypeof-1.2.0.tgz#66c9a24a73f9fc28cbe66b09fed3d33dcaf1b424"
   integrity sha512-E5LDX7Wrp85Kil5bhZv46j8jOeboKq5JMmYM3gVGdGH8xFpPWXUMsNrlODCrkoxMEeNi/XZIwuRvY4XNwYMJpw==
 
-sha.js@^2.4.0, sha.js@^2.4.8:
-  version "2.4.11"
-  resolved "https://registry.yarnpkg.com/sha.js/-/sha.js-2.4.11.tgz#37a5cf0b81ecbc6943de109ba2960d1b26584ae7"
-  integrity sha512-QMEp5B7cftE7APOjk5Y6xgrbWu+WkLVQwk8JNjZ8nKRciZaByEW6MubieAiToS7+dwvrjGhH8jRXz3MVd0AYqQ==
-  dependencies:
-    inherits "^2.0.1"
-    safe-buffer "^5.0.1"
-
-sha.js@^2.4.11:
+sha.js@^2.4.0, sha.js@^2.4.11, sha.js@^2.4.8:
   version "2.4.12"
   resolved "https://registry.yarnpkg.com/sha.js/-/sha.js-2.4.12.tgz#eb8b568bf383dfd1867a32c3f2b74eb52bdbf23f"
   integrity sha512-8LzC5+bvI45BjpfXU8V5fdU2mfeKiQe1D1gIMn7XUlF3OTUrpdJpPPH4EMAnF0DsHHdSZqCdSss5qCmJKuiO3w==