fix(pgsql-test): add index re-exports for module resolution

Add index.js and index.d.ts files to re-export the built dist bundle,
ensuring TypeScript and Jest can correctly resolve pgsql-test imports
in graphile-test tests.

Fixes CI failures where graphile-test tests could not find pgsql-test
module during TypeScript compilation.

Author: sdqede

packages/pgsql-test/index.d.ts

@@ -0,0 +1 @@
+export * from './dist';

packages/pgsql-test/index.js

@@ -0,0 +1 @@
+module.exports = require('./dist');