GitHub Actions: Use new PHP workflows

[lippserd]

This PR switches to the new PHP workflow, which combines linting, static analysis, and unit testing.

• After merging, I will update the branch protection required status checks to match the new workflow - below is a dry run showing what would happen.

./gh-update-branch-protection-checks/gh-update-branch-protection-checks.sh --repo Icinga/icingaweb2 --pr 5431 --dry-run
[INFO] Fetching PR details...
[WARNING] PR #5431 is not merged; continuing anyway...
[INFO] Target branch: main
[INFO] PR head branch: php-workflows
[INFO] PR head commit SHA: 5dcdbfde3f0cd1bf6ff587711ee7f6c7af1cc0ee
[INFO] Listing workflow runs triggered by commit 5dcdbfde3f0cd1bf6ff587711ee7f6c7af1cc0ee...
[INFO] Workflow runs: 20090022224
[INFO] Listing jobs for workflow 20090022224...
[INFO] Jobs: PHP / Test (8.2) / PHPUnit 8.2, PHP / Test (8.4) / PHPUnit 8.4, PHP / Test (8.5) / PHPUnit 8.5, PHP / Lint (8.2) / Linters 8.2, PHP / Lint (8.4) / Linters 8.4, PHP / Lint (8.3) / Linters 8.3, PHP / Static analysis (8.4) / PHPStan 8.4, PHP / Lint (8.5) / Linters 8.5, PHP / Test (8.3) / PHPUnit 8.3, PHP / Static analysis (8.5) / PHPStan 8.5, PHP / Static analysis (8.3) / PHPStan 8.3, PHP / Static analysis (8.2) / PHPStan 8.2
[INFO] Fetching current branch protection required status checks...
[INFO] Comparing branch protection required status checks...
--- /dev/fd/63	2025-12-11 11:41:57.503565172 +0100
+++ /dev/fd/62	2025-12-11 11:41:57.503811505 +0100
@@ -43,27 +43,51 @@
       },
       {
         "app_id": 15368,
-        "context": "Static analysis for php 8.2 on ubuntu-latest"
+        "context": "PHP / Lint (8.2) / Linters 8.2"
       },
       {
         "app_id": 15368,
-        "context": "Static analysis for php 8.3 on ubuntu-latest"
+        "context": "PHP / Lint (8.3) / Linters 8.3"
       },
       {
         "app_id": 15368,
-        "context": "Static analysis for php 8.4 on ubuntu-latest"
+        "context": "PHP / Lint (8.4) / Linters 8.4"
       },
       {
         "app_id": 15368,
-        "context": "Unit tests with php 8.2 on ubuntu-latest"
+        "context": "PHP / Lint (8.5) / Linters 8.5"
       },
       {
         "app_id": 15368,
-        "context": "Unit tests with php 8.3 on ubuntu-latest"
+        "context": "PHP / Static analysis (8.2) / PHPStan 8.2"
       },
       {
         "app_id": 15368,
-        "context": "Unit tests with php 8.4 on ubuntu-latest"
+        "context": "PHP / Static analysis (8.3) / PHPStan 8.3"
+      },
+      {
+        "app_id": 15368,
+        "context": "PHP / Static analysis (8.4) / PHPStan 8.4"
+      },
+      {
+        "app_id": 15368,
+        "context": "PHP / Static analysis (8.5) / PHPStan 8.5"
+      },
+      {
+        "app_id": 15368,
+        "context": "PHP / Test (8.2) / PHPUnit 8.2"
+      },
+      {
+        "app_id": 15368,
+        "context": "PHP / Test (8.3) / PHPUnit 8.3"
+      },
+      {
+        "app_id": 15368,
+        "context": "PHP / Test (8.4) / PHPUnit 8.4"
+      },
+      {
+        "app_id": 15368,
+        "context": "PHP / Test (8.5) / PHPUnit 8.5"
       }
     ],
     "contexts_url": "https://api.github.com/repos/Icinga/icingaweb2/branches/main/protection/required_status_checks/contexts",
[SUCCESS] [dry-run] No changes applied.

[lippserd]

I have updated the branch protection required status checks to match the new workflow.