Remove --experimental-strip-types flag and hashbang

- Removed hashbang from add-examples-to-dts.ts
- Removed --experimental-strip-types flag from postbuild:typescript script
- Node 22.18+ handles TypeScript natively without explicit flags

Co-authored-by: fregante <1402241+fregante@users.noreply.github.com>

Author: Copilot

add-examples-to-dts.ts

@@ -1,4 +1,3 @@
-#!/usr/bin/env node --experimental-strip-types
 /* eslint-disable n/prefer-global/process */
 import {readFileSync, writeFileSync} from 'node:fs';
 import {execSync} from 'node:child_process';