Remove remainders of gemini-scrollbar and react-gemini-scrollbar

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

package.json

@@ -72,7 +72,6 @@
     "flux": "2.1.1",
     "focus-visible": "^5.0.2",
     "fuse.js": "^2.2.0",
-    "gemini-scrollbar": "github:matrix-org/gemini-scrollbar#91e1e566",
     "gfm.css": "^1.1.1",
     "glob-to-regexp": "^0.4.1",
     "highlight.js": "^9.15.8",
@@ -93,7 +92,6 @@
     "react-beautiful-dnd": "^4.0.1",
     "react-dom": "^16.9.0",
     "react-focus-lock": "^2.2.1",
-    "react-gemini-scrollbar": "github:matrix-org/react-gemini-scrollbar#9cf17f63b7c0b0ec5f31df27da0f82f7238dc594",
     "resize-observer-polyfill": "^1.5.0",
     "sanitize-html": "^1.18.4",
     "text-encoding-utf-8": "^1.0.1",