fix: replace deprecated asyncio.get_event_loop() with modern approach (#1865)

Replace deprecated get_event_loop() with get_running_loop() and fallback
to new_event_loop() to fix the "no current event loop" warning in Python 3.10+

Author: Abdeldjalil-H

CHANGELOG.rst

@@ -13,6 +13,7 @@ Changelog
 ------
 Fixed
 ^^^^^
+- Fixed asyncio "no current event loop" deprecation warning by replacing `asyncio.get_event_loop()` with modern event loop handling using `get_running_loop()` with fallback to `new_event_loop()` (#1865)
 
 Changed
 ^^^^^^^

tortoise/contrib/test/__init__.py

@@ -126,7 +126,12 @@ def initializer(
     if db_url is not None:  # pragma: nobranch
         _TORTOISE_TEST_DB = db_url
     _CONFIG = getDBConfig(app_label=app_label, modules=_MODULES)
-    loop = loop or asyncio.get_event_loop()
+    if not loop:
+        try:
+            loop = asyncio.get_running_loop()
+        except RuntimeError:
+            loop = asyncio.new_event_loop()
+            asyncio.set_event_loop(loop)
     _LOOP = loop
     loop.run_until_complete(_init_db(_CONFIG))
     _CONNECTIONS = connections._copy_storage()