http: fix no_proxy leading-dot suffix matching

[watilde]

Fix NO_PROXY suffix matching to prevent partial domain matches

This PR improves NO_PROXY logic by ensuring suffix matches occur only on exact domains or subdomains. Previously, using endsWith() caused false positives (e.g., myexample.com matching .example.com). This aligns with the expected domain boundary matching behavior.

// Run with: ./node --expose-internals -e "$(cat this_file.js)"
'use strict';

const { parseProxyConfigFromEnv } = require('internal/http');
const assert = require('assert');

const config = parseProxyConfigFromEnv({
  http_proxy: 'http://proxy.test:8080',
  no_proxy: '.example.com',
}, 'http:', false);

// These should bypass proxy (false)
assert.strictEqual(config.shouldUseProxy('sub.example.com'), false);
assert.strictEqual(config.shouldUseProxy('example.com'), false);

// These should use proxy (true) — currently returns false without the fix
assert.strictEqual(config.shouldUseProxy('notexample.com'), true);
assert.strictEqual(config.shouldUseProxy('badexample.com'), true);

console.log('All assertions passed');

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.68%. Comparing base (56aba88) to head (abbc102).

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #62333      +/-   ##
==========================================
- Coverage   91.64%   89.68%   -1.96%     
==========================================
  Files         337      676     +339     
  Lines      140643   206579   +65936     
  Branches    21810    39563   +17753     
==========================================
+ Hits       128893   185272   +56379     
- Misses      11526    13439    +1913     
- Partials      224     7868    +7644     

Files with missing lines	Coverage Δ
lib/internal/http.js	92.11% <100.00%> (ø)

... and 460 files with indirect coverage changes

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