Bump rubocop-sorbet from 0.7.7 to 0.7.8

Bumps [rubocop-sorbet](https://github.com/shopify/rubocop-sorbet) from 0.7.7 to 0.7.8.
- [Release notes](https://github.com/shopify/rubocop-sorbet/releases)
- [Commits](Shopify/rubocop-sorbet@v0.7.7...v0.7.8)

---
updated-dependencies:
- dependency-name: rubocop-sorbet
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -51,13 +51,13 @@ GEM
       rubocop-ast (>= 1.30.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.31.1)
+    rubocop-ast (1.31.2)
       parser (>= 3.3.0.4)
     rubocop-rake (0.6.0)
       rubocop (~> 1.0)
     rubocop-shopify (2.15.1)
       rubocop (~> 1.51)
-    rubocop-sorbet (0.7.7)
+    rubocop-sorbet (0.7.8)
       rubocop (>= 0.90.0)
     ruby-progressbar (1.13.0)
     ruby2_keywords (0.0.5)