Undo the test-suite workarounds for the broken manifests

With the manifests broken, b65f265 and 4539abb worked around the symptoms:
rootJs imported itself by relative path instead of as @pezkuwi/dev, a
hand-written dynamic.d.mts stood in for the .mjs, and suite.spec.ts declared
its own describe/it/expect and imported a .d.ts at run time, which failed
the file. All three are reverted to upstream's form.

The import-attribute check now expects `with`: Node 22 removed `assert`.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

packages/dev-test/src/env/suite.spec.ts

@@ -1,12 +1,6 @@
 // Copyright 2017-2026 @pezkuwi/dev-test authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
-import '../globals.d.ts';
-
-declare const describe: import('./suite.js').Describe;
-declare const it: import('./suite.js').It;
-declare const expect: (value: unknown) => { toBe: (expected: unknown) => void; toBeDefined: () => void };
-
 describe('describe()', () => {
   // eslint-disable-next-line jest/no-focused-tests
   describe.only('.only', () => {