chore: bump @polar-sh/better-auth from 1.0.4 to 1.1.9

Bumps @polar-sh/better-auth from 1.0.4 to 1.1.9.

---
updated-dependencies:
- dependency-name: "@polar-sh/better-auth"
  dependency-version: 1.1.9
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

docs/package.json

@@ -45,7 +45,7 @@
     "@mantine/utils": "^6.0.22",
     "@mui/icons-material": "^5.16.1",
     "@mui/material": "^5.16.1",
-    "@polar-sh/better-auth": "^1.0.2",
+    "@polar-sh/better-auth": "^1.1.9",
     "@polar-sh/nextjs": "^0.4.1",
     "@polar-sh/sdk": "^0.34.2",
     "@react-email/render": "^1.1.2",