fix(lint): support TypeScript declaration merging

[noritaka1166]

Summary

• Use the TypeScript-aware @typescript-eslint/no-redeclare rule for
  TypeScript files.
• Preserve no-redeclare checks for JavaScript files.

Rationale

brianc/node-postgres#3714
updates the lint job to run on Node.js 22, which allows ESLint 10 to run
correctly.

That change exposed a no-redeclare error in pg-query-stream. The error is
a false positive from ESLint's core rule: QueryStream intentionally uses a
class/namespace declaration merge to expose the public QueryStream.Config
type.

This replaces the core rule with TypeScript ESLint's equivalent rule for
TypeScript files, which understands declaration merging.

Validation

• yarn lint
• yarn build

[brianc]

Thank you!