Enhancement: Add Php81 rule set

[localheinz]

This pull request

• adds a Php81 rule set

[codecov]

Codecov Report

Merging #521 (b6633d0) into main (c2b536b) will not change coverage.
The diff coverage is n/a.

❗ Current head b6633d0 differs from pull request most recent head 3913686. Consider uploading reports for the commit 3913686 to get more accurate results

@@             Coverage Diff             @@
##                main      #521   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
  Complexity         7         7           
===========================================
  Files              2         2           
  Lines             26        26           
===========================================
  Hits              26        26           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c2b536b...3913686. Read the comment docs.