Bump execjs from 2.7.0 to 2.8.1

Bumps [execjs](https://github.com/rails/execjs) from 2.7.0 to 2.8.1.
- [Release notes](https://github.com/rails/execjs/releases)
- [Commits](rails/execjs@v2.7.0...v2.8.1)

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

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

Author: dependabot[bot]

Gemfile.lock

@@ -148,7 +148,7 @@ GEM
       concurrent-ruby (~> 1.0)
       zeitwerk (~> 2.6)
     erubi (1.11.0)
-    execjs (2.7.0)
+    execjs (2.8.1)
     factory_bot (6.1.0)
       activesupport (>= 5.0.0)
     factory_bot_rails (6.1.0)