fix(tests): exclude arch tests from prefer-lowest CI runs

Pest arch tests don't extend TestCase, causing Laravel's
HandleExceptions::flushState() to receive null in prefer-lowest
mode with older Orchestra Testbench versions.

Changes:
- Add 'arch' group to ArchTest
- Configure CI to exclude arch group only in prefer-lowest runs
- Normal CI runs and local testing still execute arch tests

This resolves the PHPUnit\Runner\ErrorHandler::enable() TypeError
that occurred exclusively in prefer-lowest test environments.

Author: sylvesterdamgaard

.github/workflows/run-tests.yml

@@ -57,7 +57,12 @@ jobs:
         run: composer show -D
 
       - name: Execute tests
-        run: vendor/bin/pest --ci --exclude-group=redis
+        run: |
+          if [ "${{ matrix.stability }}" == "prefer-lowest" ]; then
+            vendor/bin/pest --ci --exclude-group=redis,arch
+          else
+            vendor/bin/pest --ci --exclude-group=redis
+          fi
 
   test-with-redis:
     runs-on: ubuntu-latest

tests/ArchTest.php

@@ -2,4 +2,5 @@
 
 arch('it will not use debugging functions')
     ->expect(['dd', 'dump', 'ray'])
-    ->each->not->toBeUsed();
+    ->each->not->toBeUsed()
+    ->group('arch');