Bump wkhtmltopdf-binary from 0.12.6.8 to 0.12.6.9

Bumps [wkhtmltopdf-binary](https://github.com/zakird/wkhtmltopdf_binary_gem) from 0.12.6.8 to 0.12.6.9.
- [Release notes](https://github.com/zakird/wkhtmltopdf_binary_gem/releases)
- [Changelog](https://github.com/zakird/wkhtmltopdf_binary_gem/blob/master/CHANGELOG.md)
- [Commits](https://github.com/zakird/wkhtmltopdf_binary_gem/compare/0.12.6.8...0.12.6.9)

---
updated-dependencies:
- dependency-name: wkhtmltopdf-binary
  dependency-version: 0.12.6.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -728,7 +728,7 @@ GEM
     wicked_pdf (2.8.2)
       activesupport
       ostruct
-    wkhtmltopdf-binary (0.12.6.8)
+    wkhtmltopdf-binary (0.12.6.9)
     xpath (3.2.0)
       nokogiri (~> 1.8)
     zeitwerk (2.7.2)