refactor: Removes the CSS files from the Sankey Loop plugin (#19494)

* refactor: Removes the CSS files from the Sankey Loop plugin

* Gets opacity from the theme

superset-frontend/plugins/legacy-plugin-chart-sankey-loop/package.json

@@ -2,31 +2,25 @@
   "name": "@superset-ui/legacy-plugin-chart-sankey-loop",
   "version": "0.18.25",
   "description": "Superset Legacy Chart - Sankey Diagram with Loops",
-  "sideEffects": [
-    "*.css"
+  "keywords": [
+    "superset"
   ],
+  "homepage": "https://github.com/apache-superset/superset-ui#readme",
+  "bugs": {
+    "url": "https://github.com/apache-superset/superset-ui/issues"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/apache-superset/superset-ui.git"
+  },
+  "license": "Apache-2.0",
+  "author": "Superset",
   "main": "lib/index.js",
   "module": "esm/index.js",
   "files": [
     "esm",
     "lib"
   ],
-  "repository": {
-    "type": "git",
-    "url": "git+https://github.com/apache-superset/superset-ui.git"
-  },
-  "keywords": [
-    "superset"
-  ],
-  "author": "Superset",
-  "license": "Apache-2.0",
-  "bugs": {
-    "url": "https://github.com/apache-superset/superset-ui/issues"
-  },
-  "homepage": "https://github.com/apache-superset/superset-ui#readme",
-  "publishConfig": {
-    "access": "public"
-  },
   "dependencies": {
     "d3-sankey-diagram": "^0.7.3",
     "d3-selection": "^1.4.0",
@@ -34,6 +28,10 @@
   },
   "peerDependencies": {
     "@superset-ui/chart-controls": "*",
-    "@superset-ui/core": "*"
+    "@superset-ui/core": "*",
+    "react": "^16.13.1"
+  },
+  "publishConfig": {
+    "access": "public"
   }
 }