Set lockfile version to 3

> 3: Only the new lockfile information introduced in npm version 7.
> Smaller on disk than lockfile version 2, but not interoperable with
> older npm versions. Ideal if all users are on npm version 7 and
> higher.

https://docs.npmjs.com/cli/v8/using-npm/config#lockfile-version

.npmrc

@@ -2,3 +2,4 @@ save-exact = true
 engine-strict = true
 legacy-peer-deps = true
 prefer-dedupe = true
+lockfile-version = 3