Bump rake from 13.2.1 to 13.3.1 in /backend

Bumps [rake](https://github.com/ruby/rake) from 13.2.1 to 13.3.1.
- [Release notes](https://github.com/ruby/rake/releases)
- [Changelog](https://github.com/ruby/rake/blob/master/History.rdoc)
- [Commits](ruby/rake@v13.2.1...v13.3.1)

---
updated-dependencies:
- dependency-name: rake
  dependency-version: 13.3.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

backend/Gemfile.lock

@@ -389,7 +389,7 @@ GEM
       thor (~> 1.0, >= 1.2.2)
       zeitwerk (~> 2.6)
     rainbow (3.1.1)
-    rake (13.2.1)
+    rake (13.3.1)
     rdoc (6.16.0)
       erb
       psych (>= 4.0.0)