Bump stringio from 3.1.1 to 3.1.2

Bumps [stringio](https://github.com/ruby/stringio) from 3.1.1 to 3.1.2.
- [Release notes](https://github.com/ruby/stringio/releases)
- [Changelog](https://github.com/ruby/stringio/blob/master/NEWS.md)
- [Commits](ruby/stringio@v3.1.1...v3.1.2)

---
updated-dependencies:
- dependency-name: stringio
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -310,7 +310,7 @@ GEM
       actionpack (>= 6.1)
       activesupport (>= 6.1)
       sprockets (>= 3.0.0)
-    stringio (3.1.1)
+    stringio (3.1.2)
     thor (1.3.2)
     tilt (2.4.0)
     timeout (0.4.2)