Bump image_optim from 0.26.2 to 0.26.3

Bumps [image_optim](https://github.com/toy/image_optim) from 0.26.2 to 0.26.3.
- [Release notes](https://github.com/toy/image_optim/releases)
- [Changelog](https://github.com/toy/image_optim/blob/master/CHANGELOG.markdown)
- [Commits](toy/image_optim@v0.26.2...v0.26.3)

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

Gemfile

@@ -14,7 +14,7 @@ gem 'govuk_publishing_components', '~> 11.2.0'
 gem 'govuk_app_config', '~> 1.10.0'
 
 group :development do
-  gem 'image_optim', '0.26.2'
+  gem 'image_optim', '0.26.3'
   gem 'better_errors'
   gem 'binding_of_caller'
 end

Gemfile.lock

@@ -148,7 +148,7 @@ GEM
       domain_name (~> 0.5)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    image_optim (0.26.2)
+    image_optim (0.26.3)
       exifr (~> 1.2, >= 1.2.2)
       fspath (~> 3.0)
       image_size (>= 1.5, < 3)
@@ -365,7 +365,7 @@ DEPENDENCIES
   govuk_publishing_components (~> 11.2.0)
   govuk_template (= 0.24.1)
   govuk_test
-  image_optim (= 0.26.2)
+  image_optim (= 0.26.3)
   jasmine-rails (~> 0.14.8)
   minitest
   minitest-capybara (~> 0.9.0)