ci(featureflags): add Feature flags test job and make target

Wires the `featureflags` phpunit testsuite (tests/OpenFeature) into CI per bwoebi's PR #3630 feedback. Gated to PHP 8.0+ because open-feature/sdk requires PHP 8.

Author: leoromanovsky

.gitlab/generate-tracer.php

@@ -386,6 +386,24 @@ function before_script_steps($with_docker_auth = false) {
     - make test_unit PHPUNIT_JUNIT="artifacts/tests/php-tests.xml" <?= ASSERT_NO_MEMLEAKS ?>
 <?php after_script(); ?>
 
+<?php if (version_compare($major_minor, "8.0", ">=")): ?>
+"Feature flags tests: [<?= $major_minor ?>]":
+  extends: .debug_test
+  needs:
+    - job: "compile extension: debug"
+      parallel:
+        matrix:
+          - PHP_MAJOR_MINOR: "<?= $major_minor ?>"
+            ARCH: "amd64"
+      artifacts: true
+  variables:
+    PHP_MAJOR_MINOR: "<?= $major_minor ?>"
+    ARCH: "amd64"
+  script:
+    - make test_featureflags PHPUNIT_JUNIT="artifacts/tests/php-tests.xml" <?= ASSERT_NO_MEMLEAKS ?>
+<?php after_script(); ?>
+<?php endif; ?>
+
 "API unit tests: [<?= $major_minor ?>]":
   extends: .debug_test
   needs:

Makefile

@@ -1315,6 +1315,9 @@ test_distributed_tracing_coverage:
 test_metrics: global_test_run_dependencies
 	$(call run_tests,--testsuite=metrics $(TESTS))
 
+test_featureflags: global_test_run_dependencies
+	$(call run_tests,--testsuite=featureflags $(TESTS))
+
 benchmarks_run_dependencies: global_test_run_dependencies tests/Frameworks/Symfony/Version_5_2/composer.lock-php$(PHP_MAJOR_MINOR) tests/Frameworks/Laravel/Version_10_x/composer.lock-php$(PHP_MAJOR_MINOR) tests/Benchmarks/composer.lock-php$(PHP_MAJOR_MINOR)
 	php tests/Frameworks/Symfony/Version_5_2/bin/console cache:clear --no-warmup --env=prod