Fix linting and formatting issues

Co-authored-by: MischaPanch <35432522+MischaPanch@users.noreply.github.com>

src/serena/dashboard.py

@@ -2,7 +2,7 @@ import os
 import socket
 import threading
 from collections.abc import Callable
-from datetime import datetime
+from datetime import UTC, datetime
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Self
 
@@ -148,23 +148,23 @@ class SerenaDashboardAPI:
         """
         Get the installation date ID (YYYYMMDD format) based on the creation time
         of the SERENA_HOME directory.
-        
+
         :return: Installation date as an integer in YYYYMMDD format
         """
         serena_home = SerenaPaths().serena_user_home_dir
-        
+
         # If SERENA_HOME doesn't exist yet, return today's date
         if not os.path.exists(serena_home):
-            today = datetime.now()
+            today = datetime.now(tz=UTC)
             return int(today.strftime("%Y%m%d"))
-        
+
         # Get the creation/modification time of the SERENA_HOME directory
         stat_info = os.stat(serena_home)
         # Use st_ctime on Unix-like systems (change time, closest to creation time)
         # or st_mtime if ctime is not reliable
         creation_timestamp = stat_info.st_ctime
-        creation_date = datetime.fromtimestamp(creation_timestamp)
-        
+        creation_date = datetime.fromtimestamp(creation_timestamp, tz=UTC)
+
         # Return as YYYYMMDD integer
         return int(creation_date.strftime("%Y%m%d"))
 
@@ -350,12 +350,12 @@ class SerenaDashboardAPI:
             def _get_unread_news_ids() -> list[int]:
                 all_news_files = (Path(SERENA_DASHBOARD_DIR) / "news").glob("*.html")
                 all_news_ids = [int(f.stem) for f in all_news_files]
-                
+
                 # Filter news items by installation date
                 installation_date_id = self._get_installation_date_id()
                 # Only include news items published on or after the installation date
                 all_news_ids = [news_id for news_id in all_news_ids if news_id >= installation_date_id]
-                
+
                 news_snippet_id_file = SerenaPaths().news_snippet_id_file
                 if not os.path.exists(news_snippet_id_file):
                     return all_news_ids

test/serena/test_dashboard.py

@@ -8,8 +8,6 @@ from datetime import datetime
 from pathlib import Path
 from unittest.mock import MagicMock, patch
 
-import pytest
-
 from serena.dashboard import SerenaDashboardAPI
 
 
@@ -30,7 +28,7 @@ class TestNewsDisplayLogic:
                 # Should return a valid YYYYMMDD format integer
                 assert isinstance(result, int)
                 assert 20000101 <= result <= 99991231  # Valid date range
-                
+
                 # Should match today's or recent date (since we just created the directory)
                 result_str = str(result)
                 assert len(result_str) == 8