ci/cd: fix quality checks not running on all OSes

Previously, quality checks were mistakenly configured to run only on
Ubuntu.

This commit modifies the CI/CD workflow to use the matrix strategy,
allowing the quality checks to be executed on macOS, Ubuntu and Windows.

Additionally, this update resolves the `MD034/no-bare-urls Bare URL
used` linting error that surfaced when testing on Windows.

.github/workflows/checks.quality.yaml

@@ -4,7 +4,7 @@ on: [ push, pull_request ]
 
 jobs:
   lint:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}-latest
     strategy:
       matrix:
         lint-command:

tests/checks/external-urls/StatusChecker/README.md

@@ -105,5 +105,5 @@ console.log(`Status code: ${status.code}`);
   - This is useful for websites that do not respond to HEAD requests, such as those behind certain CDN or web application firewalls.
   - Provide patterns as regular expressions (`RegExp`), allowing them to match any part of a URL.
   - Examples:
-    - To match any URL starting with "https://example.com/api": `/^https:\/\/example\.com\/api/`
-    - To match any domain ending with "cloudflare.com": `/^https:\/\/.*\.cloudflare\.com\//`
+    - To match any URL starting with `https://example.com/api`: `/^https:\/\/example\.com\/api/`
+    - To match any domain ending with `cloudflare.com`: `/^https:\/\/.*\.cloudflare\.com\//`