Bump bootsnap from 1.9.3 to 1.9.4

Bumps [bootsnap](https://github.com/Shopify/bootsnap) from 1.9.3 to 1.9.4.
- [Release notes](https://github.com/Shopify/bootsnap/releases)
- [Changelog](https://github.com/Shopify/bootsnap/blob/master/CHANGELOG.md)
- [Commits](https://github.com/Shopify/bootsnap/compare/v1.9.3...v1.9.4)

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

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

Gemfile.lock

@@ -300,7 +300,7 @@ GEM
     bindata (2.4.10)
     binding_of_caller (1.0.0)
       debug_inspector (>= 0.0.1)
-    bootsnap (1.9.3)
+    bootsnap (1.9.4)
       msgpack (~> 1.0)
     brakeman (5.2.0)
     browser (5.3.1)