feat: update default font from CentraNo1 to Geist

Replace CentraNo1 font with Geist to align with the design-tokens v8
font family migration (metamask-design-system). This matches the
@font-face declarations used in the design system's storybook-react.

- Update @metamask/design-tokens from ^7.1.0 to ^8.0.0
- Replace CentraNo1 woff2 files with Geist woff2 files (6 faces:
  Regular, RegularItalic, Medium, MediumItalic, Bold, BoldItalic)
- Update @font-face declarations in index.css

Author: georgewrmarshall

package.json

@@ -23,7 +23,7 @@
     "test": "yarn playwright test"
   },
   "dependencies": {
-    "@metamask/design-tokens": "^7.1.0",
+    "@metamask/design-tokens": "^8.0.0",
     "@metamask/object-multiplex": "^2.0.0",
     "@metamask/post-message-stream": "^8.0.0",
     "eth-phishing-detect": "^1.2.0",