Have Renovate bot refresh our lockfile for us.

I noticed that caniuse-lite wants to be updated regularly via
`npx browserslist@latest --update-db`. Renovate bot can do this if we
enable its `lockFileMaintenance` option
([source](https://github.com/renovatebot/renovate/issues/8615)).

I'm not sure exactly how annoying Renovate bot will be if we enable
this option but I figure we can just try it and disable it if it's
annoying.

renovate.json

@@ -2,6 +2,7 @@
   "extends": ["config:base"],
   "ignorePaths": ["test/"],
   "labels": ["Type: Dependencies"],
+  "lockFileMaintenance": {"enabled": true},
   "stabilityDays": 1,
   "vulnerabilityAlerts": {
     "labels": ["Type: Security"]