config: Pin sass-converter version to silence deprecation warnings

Author: gonX

site/Gemfile

@@ -21,6 +21,10 @@ gem 'json'
 gem "bootswatch", github: "thomaspark/bootswatch", tag: "v5.3.6"
 gem "bootstrap", "~> 5.3.5"
 
+# pinned version of dependency of jekyll-sass-converter, as it emits deprecation warnings until
+# bootstrap v5.5.0 - see https://github.com/OpenTabletDriver/opentabletdriver.github.io/issues/212
+gem 'sass-embedded', "~> 1.78.0"
+
 # Windows and JRuby does not include zoneinfo files, so bundle the tzinfo-data gem
 # and associated library.
 platforms :mingw, :x64_mingw, :mswin, :jruby do