Bump sass from 1.89.1 to 1.91.0 in /frontend

Bumps [sass](https://github.com/sass/dart-sass) from 1.89.1 to 1.91.0.
- [Release notes](https://github.com/sass/dart-sass/releases)
- [Changelog](https://github.com/sass/dart-sass/blob/main/CHANGELOG.md)
- [Commits](https://github.com/sass/dart-sass/compare/1.89.1...1.91.0)

---
updated-dependencies:
- dependency-name: sass
  dependency-version: 1.91.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

frontend/obsidian-plugin/package.json

@@ -23,7 +23,7 @@
         "mini-css-extract-plugin": "^2.9.2",
         "obsidian": "1.8.7",
         "resolve-url-loader": "^5.0.0",
-        "sass": "^1.89.1",
+        "sass": "^1.91.0",
         "sass-loader": "^16.0.5",
         "sync-client": "file:../sync-client",
         "terser-webpack-plugin": "^5.3.14",

frontend/package-lock.json

@@ -5190,7 +5190,9 @@
 			"license": "MIT"
 		},
 		"node_modules/sass": {
-			"version": "1.89.1",
+			"version": "1.91.0",
+			"resolved": "https://registry.npmjs.org/sass/-/sass-1.91.0.tgz",
+			"integrity": "sha512-aFOZHGf+ur+bp1bCHZ+u8otKGh77ZtmFyXDo4tlYvT7PWql41Kwd8wdkPqhhT+h2879IVblcHFglIMofsFd1EA==",
 			"dev": true,
 			"license": "MIT",
 			"dependencies": {
@@ -6375,7 +6377,7 @@
 				"obsidian": "1.8.7",
 				"reconcile-text": "^0.5.0",
 				"resolve-url-loader": "^5.0.0",
-				"sass": "^1.89.1",
+				"sass": "^1.91.0",
 				"sass-loader": "^16.0.5",
 				"sync-client": "file:../sync-client",
 				"terser-webpack-plugin": "^5.3.14",