Bump workbox-precaching from 6.2.2 to 6.2.4

Bumps [workbox-precaching](https://github.com/googlechrome/workbox) from 6.2.2 to 6.2.4.
- [Release notes](https://github.com/googlechrome/workbox/releases)
- [Commits](https://github.com/googlechrome/workbox/compare/v6.2.2...v6.2.4)

---
updated-dependencies:
- dependency-name: workbox-precaching
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

package.json

@@ -94,7 +94,7 @@
     "webcomponents.js": "^0.7.24",
     "whatwg-fetch": "^3.6.2",
     "workbox-core": "^6.2.2",
-    "workbox-precaching": "^6.2.2"
+    "workbox-precaching": "^6.2.4"
   },
   "browserslist": [
     "last 2 Firefox versions",