Use `OllamaEmbeddings` in ollama examples (#10616)

This change the Ollama examples to use `OllamaEmbeddings` for generating
embeddings.

docs/extras/integrations/chat/ollama.ipynb

@@ -132,13 +132,7 @@
     "ollama pull llama2:13b\n",
     "```\n",
     "\n",
-    "Or, the 13b-chat model:\n",
-    "\n",
-    "```\n",
-    "ollama pull llama2:13b-chat\n",
-    "```\n",
-    "\n",
-    "Let's also use local embeddings from `GPT4AllEmbeddings` and `Chroma`."
+    "Let's also use local embeddings from `OllamaEmbeddings` and `Chroma`."
    ]
   },
   {
@@ -147,7 +141,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "! pip install gpt4all chromadb"
+    "! pip install chromadb"
    ]
   },
   {
@@ -167,22 +161,14 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": null,
    "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Found model file at  /Users/rlm/.cache/gpt4all/ggml-all-MiniLM-L6-v2-f16.bin\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "from langchain.vectorstores import Chroma\n",
-    "from langchain.embeddings import GPT4AllEmbeddings\n",
+    "from langchain.embeddings import OllamaEmbeddings\n",
     "\n",
-    "vectorstore = Chroma.from_documents(documents=all_splits, embedding=GPT4AllEmbeddings())"
+    "vectorstore = Chroma.from_documents(documents=all_splits, embedding=OllamaEmbeddings())"
    ]
   },
   {
@@ -238,7 +224,7 @@
     "from langchain.chat_models import ChatOllama\n",
     "from langchain.callbacks.manager import CallbackManager\n",
     "from langchain.callbacks.streaming_stdout import StreamingStdOutCallbackHandler\n",
-    "chat_model = ChatOllama(model=\"llama2:13b-chat\",\n",
+    "chat_model = ChatOllama(model=\"llama2:13b\",\n",
     "                        verbose=True,\n",
     "                        callback_manager=CallbackManager([StreamingStdOutCallbackHandler()]))"
    ]

docs/extras/integrations/llms/ollama.ipynb

@@ -137,7 +137,6 @@
     "\n",
     "```\n",
     "ollama pull llama2:13b\n",
-    "ollama run llama2:13b \n",
     "```\n",
     "\n",
     "Let's also use local embeddings from `OllamaEmbeddings` and `Chroma`."
@@ -149,7 +148,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "! pip install gpt4all chromadb"
+    "! pip install chromadb"
    ]
   },
   {
@@ -169,17 +168,9 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 61,
+   "execution_count": null,
    "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Found model file at  /Users/rlm/.cache/gpt4all/ggml-all-MiniLM-L6-v2-f16.bin\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "from langchain.vectorstores import Chroma\n",
     "from langchain.embeddings import OllamaEmbeddings\n",