Bump terser from 4.8.0 to 4.8.1 in /samples/react-hero-webpart

Bumps [terser](https://github.com/terser/terser) from 4.8.0 to 4.8.1.
- [Release notes](https://github.com/terser/terser/releases)
- [Changelog](https://github.com/terser/terser/blob/master/CHANGELOG.md)
- [Commits](https://github.com/terser/terser/commits)

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

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

samples/react-hero-webpart/package-lock.json

@@ -20505,9 +20505,9 @@
       }
     },
     "terser": {
-      "version": "4.8.0",
-      "resolved": "https://registry.npmjs.org/terser/-/terser-4.8.0.tgz",
-      "integrity": "sha512-EAPipTNeWsb/3wLPeup1tVPaXfIaU68xMnVdPafIL1TV05OhASArYyIfFvnvJCNrR2NIOvDVNNTFRa+Re2MWyw==",
+      "version": "4.8.1",
+      "resolved": "https://registry.npmjs.org/terser/-/terser-4.8.1.tgz",
+      "integrity": "sha512-4GnLC0x667eJG0ewJTa6z/yXrbLGv80D9Ru6HIpCQmO+Q4PfEtBFi0ObSckqwL6VyQv/7ENJieXHo2ANmdQwgw==",
       "dev": true,
       "requires": {
         "commander": "^2.20.0",