Fix Python linting issues in test file

- Sort imports according to ruff standards
- Remove trailing whitespace from blank lines
- Remove unnecessary 'r' mode argument from open()
- Add trailing newline at end of file

All tests still pass after linting fixes.

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

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

tests/unit/test_lightsail_boto3_fix.py

@@ -5,11 +5,11 @@ Verifies that get_aws_connection_info() works without the deprecated boto3 param
 Addresses issue #14822.
 """
 
-import sys
-import os
-import unittest
-from unittest.mock import patch, MagicMock
 import importlib.util
+import os
+import sys
+import unittest
+from unittest.mock import MagicMock, patch
 
 # Add the library directory to the path
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), '../../library'))
@@ -112,7 +112,7 @@ class TestLightsailBoto3Fix(unittest.TestCase):
         """Verify that boto3 parameter is not present in the source code."""
         lightsail_path = os.path.join(os.path.dirname(__file__), '../../library/lightsail_region_facts.py')
 
-        with open(lightsail_path, 'r') as f:
+        with open(lightsail_path) as f:
             content = f.read()
 
         # Check that boto3=True is not in the file
@@ -134,7 +134,7 @@ class TestLightsailBoto3Fix(unittest.TestCase):
 
         lightsail_path = os.path.join(os.path.dirname(__file__), '../../library/lightsail_region_facts.py')
 
-        with open(lightsail_path, 'r') as f:
+        with open(lightsail_path) as f:
             lines = f.readlines()
 
         # Find the line that calls get_aws_connection_info