fix(sqlserver): defer yaml import and skip scenario registration when config absent

In tests/providers/scenarios.py:
- Move 'import yaml' inside _load_scenarios_from_config() so missing
  PyYAML does not break module import when scenarios are unused.
- When the scenarios config file is missing, print a friendly skip
  notice and return instead of raising FileNotFoundError, allowing
  providers/registry import to succeed without a configured environment.

Author: vistart

tests/providers/scenarios.py

@@ -25,23 +25,19 @@ def get_enabled_scenarios() -> Dict[str, Any]:
 
 
 def _load_scenarios_from_config():
-    import yaml
-
     env_config_path = os.getenv("SQLSERVER_SCENARIOS_CONFIG_PATH")
     if env_config_path and os.path.exists(env_config_path):
         print(f"Loading SQL Server scenarios from environment-specified path: {env_config_path}")
         config_path = env_config_path
     else:
         config_path = os.path.join(os.path.dirname(__file__), "..", "config", "sqlserver_scenarios.yaml")
         if not os.path.exists(config_path):
-            raise FileNotFoundError(
-                "No SQL Server scenarios configuration file found. "
-                "Either set SQLSERVER_SCENARIOS_CONFIG_PATH environment variable "
-                "or place sqlserver_scenarios.yaml in the tests/config directory."
-            )
+            print("No SQL Server scenarios configuration file found. Skipping scenario registration.")
+            return
         print(f"Loading SQL Server scenarios from default path: {config_path}")
 
     try:
+        import yaml
         with open(config_path, 'r', encoding='utf-8') as f:
             config_data = yaml.safe_load(f)