Improve performance of plan and spec loaders

Ensure to not read source file for each frame when getting frames
from the stack

src/e3/anod/loader.py

@@ -277,9 +277,13 @@ def spec(name: str) -> Callable[..., Anod]:
     :param name: name of the spec to load
     """
     spec_repository: AnodSpecRepository | None = None
-    for k in inspect.stack()[1:]:
-        if "__spec_repository" in k[0].f_globals:
-            spec_repository = k[0].f_globals["__spec_repository"]
+
+    # Implementation note: context=0 means that the no source context is
+    # computed for each frame. This improve drastically the performance
+    # as it avoids reading the source file for each frame.
+    for k in inspect.stack(context=0)[1:]:
+        spec_repository = k[0].f_globals.get("__spec_repository")
+        if spec_repository is not None:
             break
 
     assert spec_repository is not None

src/e3/electrolyt/plan.py

@@ -292,7 +292,12 @@ def _add_action(self, name: str, *args: Any, **kwargs: Any) -> None:
         plan_line = "unknown filename:unknown lineno"
         # Retrieve the plan line
         try:
-            caller_frames = inspect.getouterframes(frame=inspect.currentframe())
+            # Implementation note: context=0 means that the no source context is
+            # computed for each frame. This improve drastically the performance
+            # as it avoids reading the source file for each frame.
+            caller_frames = inspect.getouterframes(
+                frame=inspect.currentframe(), context=0
+            )
             caller_frames_in_plan = []
             for frame in caller_frames:
                 frame_filename = frame.filename