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] <[email protected]>

Gemfile.lock

@@ -112,6 +112,7 @@ GEM
       ssrf_filter (~> 1.0)
     carrierwave_backgrounder (0.4.3)
       carrierwave (>= 0.5, < 2.2)
+    childprocess (5.0.0)
     chunky_png (1.4.0)
     colorize (1.1.0)
     concurrent-ruby (1.2.3)
@@ -243,10 +244,11 @@ GEM
       kaminari-core (= 1.2.2)
     kaminari-core (1.2.2)
     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)
     lograge (0.14.0)
       actionpack (>= 4)
       activesupport (>= 4)