ci: remove PHP 7.3/7.4 from matrix, require PHP 8.0+

Agent-Logs-Url: https://github.com/voku/Arrayy/sessions/12756e7f-df38-4475-b502-db0e98aa2a69

Co-authored-by: voku <264695+voku@users.noreply.github.com>

Author: Copilot

.github/workflows/ci.yml

@@ -17,14 +17,12 @@ jobs:
       fail-fast: false
       matrix:
         php: [
-            7.3,
-            7.4,
             8.0,
             8.1
         ]
         composer: [basic]
         include:
-          - php: 7.3
+          - php: 8.0
             composer: lowest
     timeout-minutes: 10
     steps: