Bump listen from 3.7.0 to 3.7.1 in /backend

Bumps [listen](https://github.com/guard/listen) from 3.7.0 to 3.7.1.
- [Release notes](https://github.com/guard/listen/releases)
- [Commits](guard/listen@v3.7.0...v3.7.1)

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

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

Author: dependabot[bot]

backend/Gemfile.lock

@@ -80,15 +80,15 @@ GEM
     concurrent-ruby (1.1.9)
     crass (1.0.6)
     erubi (1.10.0)
-    ffi (1.15.3)
+    ffi (1.15.5)
     globalid (1.0.0)
       activesupport (>= 5.0)
     i18n (1.10.0)
       concurrent-ruby (~> 1.0)
     jbuilder (2.11.5)
       actionview (>= 5.0.0)
       activesupport (>= 5.0.0)
-    listen (3.7.0)
+    listen (3.7.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     loofah (2.14.0)
@@ -146,7 +146,7 @@ GEM
       rake (>= 12.2)
       thor (~> 1.0)
     rake (13.0.6)
-    rb-fsevent (0.11.0)
+    rb-fsevent (0.11.1)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     regexp-examples (1.5.1)