Bump rubocop-shopify from 2.14.0 to 2.15.1

Bumps [rubocop-shopify](https://github.com/Shopify/ruby-style-guide) from 2.14.0 to 2.15.1.
- [Release notes](https://github.com/Shopify/ruby-style-guide/releases)
- [Commits](Shopify/ruby-style-guide@v2.14.0...v2.15.1)

---
updated-dependencies:
- dependency-name: rubocop-shopify
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -47,7 +47,7 @@ GEM
       unicode-display_width (>= 2.4.0, < 3.0)
     rubocop-ast (1.31.2)
       parser (>= 3.3.0.4)
-    rubocop-shopify (2.14.0)
+    rubocop-shopify (2.15.1)
       rubocop (~> 1.51)
     ruby-progressbar (1.13.0)
     unicode-display_width (2.5.0)