build(deps): bump strong_migrations from 1.8.0 to 2.0.0 (#5873)

Bumps [strong_migrations](https://github.com/ankane/strong_migrations) from 1.8.0 to 2.0.0.
- [Changelog](https://github.com/ankane/strong_migrations/blob/master/CHANGELOG.md)
- [Commits](ankane/strong_migrations@v1.8.0...v2.0.0)

---
updated-dependencies:
- dependency-name: strong_migrations
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -304,7 +304,7 @@ GEM
     mini_magick (4.11.0)
     mini_mime (1.1.5)
     mini_portile2 (2.8.7)
-    minitest (5.23.1)
+    minitest (5.24.1)
     multi_xml (0.7.1)
       bigdecimal (~> 3.1)
     multipart-post (2.4.1)
@@ -526,8 +526,8 @@ GEM
     stimulus-rails (1.3.3)
       railties (>= 6.0.0)
     stringio (3.1.0)
-    strong_migrations (1.8.0)
-      activerecord (>= 5.2)
+    strong_migrations (2.0.0)
+      activerecord (>= 6.1)
     strscan (3.1.0)
     thor (1.3.1)
     timeout (0.4.1)