fix(test): skip v8 coverage on pool-workers suite

workerd has no node:inspector/promises module, which @vitest/coverage-v8
requires. Coverage now runs only on the happy-dom suite; the
pool-workers suite still runs (verifying behavior) but does not
contribute to the coverage report. Trade-off: covered % drops because
many tests moved to pool-workers. Acceptable — tests still execute,
and switching the coverage backend (e.g. istanbul) is a separate
decision.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: fullstackjam

package.json

@@ -15,7 +15,7 @@
 		"test:run": "vitest run && vitest run --config vitest.workers.config.ts",
 		"test:happy-dom": "vitest run",
 		"test:workers": "vitest run --config vitest.workers.config.ts",
-		"test:coverage": "vitest run --coverage && vitest run --config vitest.workers.config.ts --coverage",
+		"test:coverage": "vitest run --coverage && vitest run --config vitest.workers.config.ts",
 		"lint": "eslint .",
 		"lint:fix": "eslint . --fix",
 		"format": "prettier --write .",