module: fix require of imports with package map

[lazerg]

With --experimental-package-map, Module._resolveFilename sent every non-relative request to the package map, # specifiers included. The map has no entry for them, so require('#x') threw MODULE_NOT_FOUND before the package.json "imports" lookup could run. This skips the map for # requests, which matches the documented require() algorithm and what the ESM resolver already does.

Fixes: #66562

[nodejs-github-bot]

Review requested:

• @nodejs/loaders

[github-actions]

Caution

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.43%. Comparing base (1bcf30b) to head (243c4ca).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #66565      +/-   ##
==========================================
- Coverage   92.77%   90.43%   -2.34%     
==========================================
  Files         422      791     +369     
  Lines      193590   276516   +82926     
  Branches    29859    53093   +23234     
==========================================
+ Hits       179597   250073   +70476     
- Misses      13664    16850    +3186     
- Partials      329     9593    +9264     

Files with missing lines	Coverage Δ
lib/internal/modules/cjs/loader.js	97.99% <100.00%> (+19.19%)	⬆️

... and 499 files with indirect coverage changes

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[aduh95]

nit

Suggested change

	const { status, stdout, stderr } = spawnSync(process.execPath, [
	'--no-warnings',
	'--experimental-package-map', packageMapPath,
	'-e',
	`const root = require('#root'); console.log(root.default);`,
	], {
	cwd: fixtures.path('package-map/root'),
	encoding: 'utf8',
	});
	assert.strictEqual(stderr, '');
	assert.match(stdout, /root-package/);
	assert.strictEqual(status, 0, stderr);
	spawnSyncAndAssert(process.execPath, [
	'--no-warnings',
	'--experimental-package-map', packageMapPath,
	'-e',
	`const root = require('#root'); console.log(root.default);`,
	], {
	cwd: fixtures.path('package-map/root'),
	encoding: 'utf8',
	}, {
	stderr: '',
	stdout: /root-package/,
	});