Bump letter_opener from 1.9.0 to 1.10.0

Bumps [letter_opener](https://github.com/ryanb/letter_opener) from 1.9.0 to 1.10.0.
- [Changelog](https://github.com/ryanb/letter_opener/blob/master/CHANGELOG.md)
- [Commits](ryanb/letter_opener@v1.9.0...v1.10.0)

---
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

@@ -131,6 +131,7 @@ GEM
       rack-test (>= 0.6.3)
       regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
+    childprocess (5.0.0)
     city-state (1.1.0)
       rubyzip (>= 2.3)
     coderay (1.1.3)
@@ -258,10 +259,11 @@ GEM
       activesupport (>= 5.0.0)
     json (2.7.1)
     language_server-protocol (3.17.0.3)
-    launchy (2.5.2)
+    launchy (3.0.0)
       addressable (~> 2.8)
-    letter_opener (1.9.0)
-      launchy (>= 2.2, < 3)
+      childprocess (~> 5.0)
+    letter_opener (1.10.0)
+      launchy (>= 2.2, < 4)
     lint_roller (1.1.0)
     listen (3.9.0)
       rb-fsevent (~> 0.10, >= 0.10.3)