chore(deps-dev): bump microbundle from 0.12.3 to 0.12.4

Bumps [microbundle](https://github.com/developit/microbundle) from 0.12.3 to 0.12.4.
- [Release notes](https://github.com/developit/microbundle/releases)
- [Changelog](https://github.com/developit/microbundle/blob/master/CHANGELOG.md)
- [Commits](developit/microbundle@0.12.3...v0.12.4)

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

package.json

@@ -47,7 +47,7 @@
     "eslint-plugin-jest": "^24.0.2",
     "jest": "^26.4.2",
     "jest-puppeteer": "^4.4.0",
-    "microbundle": "^0.12.3",
+    "microbundle": "^0.12.4",
     "npm-run-all": "^4.1.5",
     "puppeteer": "5.3.1"
   }