Remove Charts tab and related Vega components from Sketch

Co-Authored-By: sketch <hello@sketch.dev>

- Removed Charts tab from navigation
- Removed sketch-charts component and vega-embed component
- Removed vega, vega-lite, and vega-embed dependencies from package.json
- Removed all associated code and UI elements
diff --git a/webui/package.json b/webui/package.json
index a330776..0248c77 100644
--- a/webui/package.json
+++ b/webui/package.json
@@ -30,10 +30,7 @@
     "lit": "^3.2.1",
     "marked": "^15.0.7",
     "mermaid": "^11.6.0",
-    "sanitize-html": "^2.15.0",
-    "vega": "^5.33.0",
-    "vega-embed": "^6.29.0",
-    "vega-lite": "^5.23.0"
+    "sanitize-html": "^2.15.0"
   },
   "devDependencies": {
     "@sand4rt/experimental-ct-web": "^1.51.1",