Bump mem from 1.1.0 to 4.0.0 (#487)

Bumps [mem](https://github.com/sindresorhus/mem) from 1.1.0 to 4.0.0.
- [Release notes](https://github.com/sindresorhus/mem/releases)
- [Commits](sindresorhus/memoize@v1.1.0...v4.0.0)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Jake Champion <me@jakechampion.name>

package.json

@@ -73,7 +73,7 @@
     "lodash": "^4.17.21",
     "lru-cache": "^6.0.0",
     "measured": "^1.0.0",
-    "mem": "^1.1.0",
+    "mem": "^4.0.0",
     "merge-deep": "^3.0.3",
     "merge-stream": "^2.0.0",
     "mime": "^1.6.0",