Remove PHPUnit startup diagnostics

The diagnostics have served their purpose: phpunit --version,
--list-tests, and standalone bootstrap all run fine, so the segfault
is specific to test execution (likely inside WP_SQLite_Driver's setUp
path). Drop the step to keep the workflow focused on the pass/fail
signal.

Author: JanJakes

.github/workflows/phpunit-tests-turso.yml

@@ -123,19 +123,6 @@ jobs:
           ignore-cache: "yes"
           composer-options: "--optimize-autoloader"
 
-      - name: Diagnose PHPUnit startup under Turso
-        continue-on-error: true
-        env:
-          LD_PRELOAD: ${{ steps.turso-lib.outputs.path }}
-        working-directory: packages/mysql-on-sqlite
-        run: |
-          echo '--- phpunit --version ---'
-          php ./vendor/bin/phpunit --version; echo "exit=$?"
-          echo '--- phpunit --list-tests (first 5 lines) ---'
-          php ./vendor/bin/phpunit -c ./phpunit.xml.dist --list-tests 2>&1 | head -5; echo "exit=${PIPESTATUS[0]}"
-          echo '--- standalone bootstrap ---'
-          php -r 'require __DIR__ . "/tests/bootstrap.php"; echo "bootstrap ok\n";'; echo "exit=$?"
-
       - name: Run PHPUnit tests against Turso DB
         continue-on-error: true
         env: