Add Serena version to server startup logs

This change adds the Serena version number to the server startup log message, making it easier to identify which version is running when reviewing logs.

src/serena/agent.py

@@ -24,6 +24,7 @@ from multilspy import SyncLanguageServer
 from multilspy.multilspy_config import Language, MultilspyConfig
 from multilspy.multilspy_logger import MultilspyLogger
 from multilspy.multilspy_types import SymbolKind
+from serena import __version__
 from serena.gui_log_viewer import GuiLogViewer, GuiLogViewerHandler
 from serena.llm.prompt_factory import PromptFactory
 from serena.symbol import SymbolLocation, SymbolManager
@@ -88,7 +89,7 @@ class SerenaAgent:
                 Logger.root.addHandler(self._gui_log_handler)
 
         log.info(
-            f"Starting serena server for project {project_file_path} (language={self.language}, root={self.project_root}); "
+            f"Starting serena server v{__version__} for project {project_file_path} (language={self.language}, root={self.project_root}); "
             f"process id={os.getpid()}, parent process id={os.getppid()}"
         )