fix: Remove OpenAI dependency for memory reset when using alternative LLMs

- Add environment variables for default embedding provider
- Support Ollama as default embedding provider
- Add tests for memory reset with different providers
- Update documentation

Fixes #2023

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

tests/memory/test_memory_reset.py

@@ -2,6 +2,10 @@ import os
 import tempfile
 import pytest
 from crewai.memory import ShortTermMemory, LongTermMemory, EntityMemory
+from crewai.utilities.exceptions.embedding_exceptions import (
+    EmbeddingConfigurationError,
+    EmbeddingProviderError
+)
 from crewai.utilities import EmbeddingConfigurator
 
 @pytest.fixture
@@ -32,3 +36,26 @@ def test_memory_reset_with_openai(temp_db_dir):
     ]
     for memory in memories:
         memory.reset()
+
+def test_memory_reset_with_invalid_provider(temp_db_dir):
+    os.environ["CREWAI_EMBEDDING_PROVIDER"] = "invalid_provider"
+    with pytest.raises(EmbeddingProviderError):
+        memories = [
+            ShortTermMemory(path=temp_db_dir),
+            LongTermMemory(path=temp_db_dir),
+            EntityMemory(path=temp_db_dir)
+        ]
+        for memory in memories:
+            memory.reset()
+
+def test_memory_reset_with_missing_ollama_url(temp_db_dir):
+    os.environ["CREWAI_EMBEDDING_PROVIDER"] = "ollama"
+    os.environ.pop("CREWAI_OLLAMA_URL", None)
+    # Should use default URL when CREWAI_OLLAMA_URL is not set
+    memories = [
+        ShortTermMemory(path=temp_db_dir),
+        LongTermMemory(path=temp_db_dir),
+        EntityMemory(path=temp_db_dir)
+    ]
+    for memory in memories:
+        memory.reset()