frames: make FunctionCallResultFrame a SystemFrame

CHANGELOG.md

@@ -53,6 +53,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- `FunctionCallResultFrame`a are now system frames. This is to prevent function
+  call results to be discarded during interruptions.
+
 - Pipecat services have been reorganized into packages. Each package can have
   one or more of the following modules (in the future new module names might be
   needed) depending on the services implemented:

src/pipecat/frames/frames.py

@@ -377,25 +377,6 @@ class LLMEnablePromptCachingFrame(DataFrame):
     enable: bool
 
 
-@dataclass
-class FunctionCallResultProperties:
-    """Properties for a function call result frame."""
-
-    run_llm: Optional[bool] = None
-    on_context_updated: Optional[Callable[[], Awaitable[None]]] = None
-
-
-@dataclass
-class FunctionCallResultFrame(DataFrame):
-    """A frame containing the result of an LLM function (tool) call."""
-
-    function_name: str
-    tool_call_id: str
-    arguments: Any
-    result: Any
-    properties: Optional[FunctionCallResultProperties] = None
-
-
 @dataclass
 class TTSSpeakFrame(DataFrame):
     """A frame that contains a text that should be spoken by the TTS in the
@@ -652,6 +633,25 @@ class FunctionCallCancelFrame(SystemFrame):
     tool_call_id: str
 
 
+@dataclass
+class FunctionCallResultProperties:
+    """Properties for a function call result frame."""
+
+    run_llm: Optional[bool] = None
+    on_context_updated: Optional[Callable[[], Awaitable[None]]] = None
+
+
+@dataclass
+class FunctionCallResultFrame(SystemFrame):
+    """A frame containing the result of an LLM function (tool) call."""
+
+    function_name: str
+    tool_call_id: str
+    arguments: Any
+    result: Any
+    properties: Optional[FunctionCallResultProperties] = None
+
+
 @dataclass
 class STTMuteFrame(SystemFrame):
     """System frame to mute/unmute the STT service."""