Fix knowledge sources not being added to agents and crews

Co-Authored-By: Joe Moura <joao@crewai.com>

tests/test_agent_without_knowledge_uses_crew_knowledge.py

@@ -0,0 +1,45 @@
+import pytest
+from unittest.mock import patch, MagicMock
+
+from crewai import Agent, Task, Crew, Process, LLM
+from crewai.knowledge.source.string_knowledge_source import StringKnowledgeSource
+from crewai.knowledge.knowledge import Knowledge
+
+
+def test_agent_without_knowledge_uses_crew_knowledge():
+    """Test that an agent without knowledge sources can use crew knowledge sources."""
+    content = "John is 30 years old and lives in San Francisco."
+    string_source = StringKnowledgeSource(content=content)
+
+    agent = Agent(
+        role="Information Agent",
+        goal="Provide information based on knowledge sources",
+        backstory="You have access to specific knowledge sources.",
+        llm=LLM(model="gpt-4o-mini"),
+    )
+
+    task = Task(
+        description="How old is John and where does he live?",
+        expected_output="John's age and location.",
+        agent=agent,
+    )
+
+    with patch('crewai.knowledge.knowledge.Knowledge.query', return_value=[{"context": content}]) as mock_query:
+        crew = Crew(
+            agents=[agent],
+            tasks=[task],
+            process=Process.sequential,
+            knowledge_sources=[string_source],
+        )
+        
+        agent.crew = crew
+        
+        with patch.object(Agent, '_get_knowledge_search_query', return_value="test query"):
+            with patch.object(Agent, '_execute_without_timeout', return_value="John is 30 years old and lives in San Francisco."):
+                result = agent.execute_task(task)
+                
+                assert mock_query.called
+                
+                assert hasattr(agent, 'crew_knowledge_context')
+                
+                assert "John" in result