Bump sassc-embedded from 1.70.1 to 1.80.1

Note: Since we update to 1.80.1 deprecation warnings are appear when execute the assets:precompile command.
In order to silence this deprecation, we add silence_deprecation option in sass.rb initializer.

The code has also been updated to remove the deprecation warnings that appeared related to the function
darken(), lighten() and "Using / for division" instead of the function calc().

Bumps [sassc-embedded](https://github.com/sass-contrib/sassc-embedded-shim-ruby) from 1.70.1 to 1.80.1.
- [Commits](https://github.com/sass-contrib/sassc-embedded-shim-ruby/compare/v1.70.1...v1.80.1)

---
updated-dependencies:
- dependency-name: sassc-embedded
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

app/assets/stylesheets/admin/locales/form.scss

@@ -13,7 +13,7 @@
 
   > select + fieldset,
   > fieldset + fieldset {
-    margin-top: $line-height / 2;
+    margin-top: calc($line-height / 2);
   }
 
   > [type="hidden"] + fieldset,