Dev: reuse GitHub Action workflows

[kenjis]

TODO

• create codeigniter4/.github repository
• add workflows in codeigniter4/.github based on shield
  • Add workflows .github#1
  • Add workflow_call .github#2
  • Use inputs in phpcpd.yml .github#3
    • Add missing on.workflow_call.inputs in phpcpd.yml .github#5
    • fix: options are not required .github#6
  • Add concurrency and permissions .github#4
  • Add workflow for PHPUnit without database testing .github#15
• reuse workflows
  • shield
    • chore: use workflows in codeigniter4/.github shield#811
    • chore: use codeigniter4/.github/.github/workflows/phpcpd.yml shield#813
    • chore: fix phpunit workflow shield#863
  • tasks
    • chore: reuse github workflows tasks#128
  • settings
    • chore: reuse github workflows settings#95
    • chore: add phpunit-lowest.yml settings#102
  • cache
    • chore: reuse github workflows cache#16
    • chore: fix phpunit.yml cache#20
  • website
    • chore: reuse github workflows codeigniter4projects/website#399
• Fix on section in caller workflows .github#14

References

• https://docs.github.com/en/actions/using-workflows/reusing-workflows