fix: Skip YAML/TOML tests when optional dependencies unavailable

Fixed test failures in CI environments without PyYAML or toml/tomli:

**Problem:**
- test_parse_yaml_config and test_parse_toml_config were failing in CI
- Tests expected ImportError but parse_config_file() doesn't raise it
- Instead, it adds error to parse_errors list and returns empty settings
- Tests then failed on `assertGreater(len(config_file.settings), 0)`

**Solution:**
- Check parse_errors for dependency messages after parsing
- Skip test if "PyYAML not installed" found in errors
- Skip test if "toml...not installed" found in errors
- Allows tests to pass locally (with deps) and skip in CI (without deps)

**Affected Tests:**
- test_parse_yaml_config - now skips without PyYAML
- test_parse_toml_config - now skips without toml/tomli

**CI Impact:**
- Was: 2 failures across all 6 CI jobs (12 total failures)
- Now: 2 skips across all 6 CI jobs (expected behavior)

These are optional dependencies not included in base install,
so skipping is the correct behavior for CI.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

tests/test_config_extractor.py

@@ -158,12 +158,14 @@ logging:
         file_path.write_text(yaml_content)
 
         # This will skip if PyYAML not available
-        try:
-            self.parser.parse_config_file(config_file)
-            self.assertGreater(len(config_file.settings), 0)
-        except ImportError:
+        self.parser.parse_config_file(config_file)
+
+        # Check if parsing failed due to missing PyYAML
+        if config_file.parse_errors and "PyYAML not installed" in str(config_file.parse_errors):
             self.skipTest("PyYAML not installed")
 
+        self.assertGreater(len(config_file.settings), 0)
+
     def test_parse_env_file(self):
         """Test parsing .env file"""
         env_content = """
@@ -314,12 +316,14 @@ endpoint = "https://api.example.com"
         file_path.write_text(toml_content)
 
         # This will skip if toml/tomli not available
-        try:
-            self.parser.parse_config_file(config_file)
-            self.assertGreater(len(config_file.settings), 0)
-        except ImportError:
+        self.parser.parse_config_file(config_file)
+
+        # Check if parsing failed due to missing toml/tomli
+        if config_file.parse_errors and ("toml" in str(config_file.parse_errors).lower() and "not installed" in str(config_file.parse_errors)):
             self.skipTest("toml/tomli not installed")
 
+        self.assertGreater(len(config_file.settings), 0)
+
 
 class TestConfigPatternDetector(unittest.TestCase):
     """Tests for ConfigPatternDetector - pattern detection"""