Bump letter_opener from 1.7.0 to 1.8.1

Bumps [letter_opener](https://github.com/ryanb/letter_opener) from 1.7.0 to 1.8.1.
- [Release notes](https://github.com/ryanb/letter_opener/releases)
- [Changelog](https://github.com/ryanb/letter_opener/blob/master/CHANGELOG.md)
- [Commits](https://github.com/ryanb/letter_opener/compare/v1.7.0...v1.8.1)

---
updated-dependencies:
- dependency-name: letter_opener
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -280,8 +280,8 @@ GEM
     kaminari-core (1.2.2)
     launchy (2.5.0)
       addressable (~> 2.7)
-    letter_opener (1.7.0)
-      launchy (~> 2.2)
+    letter_opener (1.8.1)
+      launchy (>= 2.2, < 3)
     listen (3.7.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
@@ -352,7 +352,7 @@ GEM
     pry (0.14.1)
       coderay (~> 1.1)
       method_source (~> 1.0)
-    public_suffix (4.0.6)
+    public_suffix (4.0.7)
     puma (5.6.4)
       nio4r (~> 2.0)
     questiongenerator (1.0.0)