build(deps-dev): bump tar from 7.5.16 to 7.5.21 in /src/ifctester/webapp

Bumps [tar](https://github.com/isaacs/node-tar) from 7.5.16 to 7.5.21.
- [Release notes](https://github.com/isaacs/node-tar/releases)
- [Changelog](https://github.com/isaacs/node-tar/blob/main/CHANGELOG.md)
- [Commits](https://github.com/isaacs/node-tar/compare/v7.5.16...v7.5.21)

---
updated-dependencies:
- dependency-name: tar
  dependency-version: 7.5.21
  dependency-type: indirect
...

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

src/ifctester/webapp/package-lock.json

@@ -3177,9 +3177,9 @@
       }
     },
     "node_modules/tar": {
-      "version": "7.5.16",
-      "resolved": "https://registry.npmjs.org/tar/-/tar-7.5.16.tgz",
-      "integrity": "sha512-56adEpPMouktRlBLXiaYFFzZ/3+JXa8P9n7WbR+ibIjtviN55mEaOkiysCnPnWm+7kkui1Dn8J9l+g6zV8731w==",
+      "version": "7.5.21",
+      "resolved": "https://registry.npmjs.org/tar/-/tar-7.5.21.tgz",
+      "integrity": "sha512-XdhtCvlMywwxpCW8YEq3lOXBJpUPTR2OHHcwLPO3HwsJqOHa2Ok/oJ7ruGzp+JrKoRPVCzJwAdEjqLW/vNRPHA==",
       "dev": true,
       "license": "BlueOak-1.0.0",
       "dependencies": {