[BUG]: drizzle-kit generate fails with "fkX.isNameExplicit is not a function" on schemas with multiple foreign keys (beta.2+)

### Report hasn't been filed before.

- [x] I have verified that the bug I'm about to report hasn't been filed before.

### What version of `drizzle-orm` are you using?

drizzle-kit@1.0.0-beta.2-6565b14

### What version of `drizzle-kit` are you using?

drizzle-kit@1.0.0-beta.2-6565b14

### Other packages

_No response_

### Describe the Bug

Description:

When running drizzle-kit generate on a PostgreSQL schema with multiple foreign keys, the command fails with the error fkX.isNameExplicit is not a function (where X is a number like 5, 6, etc.).

Affected Versions:
❌ drizzle-kit@1.0.0-beta.2-6565b14 - fails
❌ drizzle-kit@1.0.0-beta.6-4414a19 - fails
❌ drizzle-kit@1.0.0-beta.8-734e789 - fails
✅ drizzle-kit@1.0.0-beta.1-867d080 - works

Environment:
- Node.js: v23.11.0
- pnpm: 10.26.2
- OS: macOS (darwin)
- Project type: ESM ("type": "module")