Update coding standard from PSR-2 to PSR-12

[jlnarvaez]

Purpose of this pull request

This pull request (PR) updates PSR-2 to PSR-12 that is a extended version of deprecated PSR-2.
Extracted from official documentation:

Deprecated - As of 2019-08-10 PSR-2 has been marked as deprecated. PSR-12 is now recommended as an alternative.

Affected pages

• https://developer.adobe.com/commerce/php/coding-standards/php/

Links to Magento Open Source code

• Upgrade PSR2 -> PSR12 for ControlStructureSpacing magento/magento-coding-standard#416

[jeff-matthews]

Thanks @jlnarvaez, but there's already a PR open for this update that I'm trying to validate with internal teams (#92).

[jeff-matthews]

Actually, I'm going to reopen your PR @jlnarvaez because you've signed the Adobe CLA and the contributor who opened #92 has not.

[jeff-matthews]

Need to wait for the PR in the coding standards repo to be merged before updating docs.

magento/magento-coding-standard#416

[github-actions]

🔍 Linter Report

Click to expand full report

═══════════════════════════════════════════════════════════════
                     LINTER REPORT
═══════════════════════════════════════════════════════════════

Generated: 2026-06-15T23:32:31.376Z
Mode: Full Linting (all rules + dead links check)
Target Directory: /home/runner/work/commerce-php/commerce-php
Skipped Rules:
  - check-frontmatter → src/pages/includes

───────────────────────────────────────────────────────────────

Files to process: 1


═══════════════════════════════════════════════════════════════
                        SUMMARY
═══════════════════════════════════════════════════════════════

  📁 Files processed:    1
  📄 Files with issues:  0
  ❌ Total errors:       0
  ⚠️  Total warnings:     0
  📋 Total issues:       0

Result: ✅ PASSED - All files passed linting successfully!

═══════════════════════════════════════════════════════════════

---

This comment was automatically generated by the linter bot.