docs: Change Pull Request to Merge Request in GitLab notebook (#25649)

- **Description:** In GitLab we call these "merge requests" rather than
"pull requests" so I thought I'd go ahead and update the notebook.
- **Issue:** N/A
- **Dependencies:** none
- **Twitter handle:** N/A

Thanks for creating the tools and notebook to help people work with
GitLab. I thought I'd contribute some minor docs updates here.

docs/docs/integrations/tools/gitlab.ipynb

@@ -23,7 +23,7 @@
     "\n",
     "3. **Comment on Issue**- posts a comment on a specific issue.\n",
     "\n",
-    "4. **Create Pull Request**- creates a pull request from the bot's working branch to the base branch.\n",
+    "4. **Create Merge Request**- creates a merge request from the bot's working branch to the base branch.\n",
     "\n",
     "5. **Create File**- creates a new file in the repository.\n",
     "\n",
@@ -82,7 +82,7 @@
     "* **GITLAB_PERSONAL_ACCESS_TOKEN**- The personal access token you created in the last step\n",
     "* **GITLAB_REPOSITORY**- The name of the Gitlab repository you want your bot to act upon. Must follow the format {username}/{repo-name}.\n",
     "* **GITLAB_BRANCH**- The branch where the bot will make its commits. Defaults to 'main.'\n",
-    "* **GITLAB_BASE_BRANCH**- The base branch of your repo, usually either 'main' or 'master.' This is where pull requests will base from. Defaults to 'main.'\n"
+    "* **GITLAB_BASE_BRANCH**- The base branch of your repo, usually either 'main' or 'master.' This is where merge requests will base from. Defaults to 'main.'\n"
    ]
   },
   {
@@ -185,14 +185,14 @@
       "</html>\n",
       ">>>> NEW\u001b[0m\n",
       "Observation: \u001b[36;1m\u001b[1;3mUpdated file game.html\u001b[0m\n",
-      "Thought:\u001b[32;1m\u001b[1;3m I need to create a pull request to submit my changes.\n",
+      "Thought:\u001b[32;1m\u001b[1;3m I need to create a merge request to submit my changes.\n",
-      "Action: Create Pull Request\n",
+      "Action: Create Merge Request\n",
       "Action Input: Add tic-tac-toe game\n",
       "\n",
       "added tic-tac-toe game, closes issue #15\u001b[0m\n",
-      "Observation: \u001b[36;1m\u001b[1;3mSuccessfully created PR number 12\u001b[0m\n",
+      "Observation: \u001b[36;1m\u001b[1;3mSuccessfully created MR number 12\u001b[0m\n",
       "Thought:\u001b[32;1m\u001b[1;3m I now know the final answer.\n",
-      "Final Answer: I have created a pull request with number 12 that solves issue 15.\u001b[0m\n",
+      "Final Answer: I have created a merge request with number 12 that solves issue 15.\u001b[0m\n",
       "\n",
       "\u001b[1m> Finished chain.\u001b[0m\n"
      ]
@@ -200,7 +200,7 @@
     {
      "data": {
       "text/plain": [
-       "'I have created a pull request with number 12 that solves issue 15.'"
+       "'I have created a merge request with number 12 that solves issue 15.'"
       ]
      },
      "execution_count": 8,
@@ -210,7 +210,7 @@
    ],
    "source": [
     "agent.run(\n",
-    "    \"You have the software engineering capabilities of a Google Principle engineer. You are tasked with completing issues on a gitlab repository. Please look at the open issues and complete them by creating pull requests that solve the issues.\"\n",
+    "    \"You have the software engineering capabilities of a Google Principle engineer. You are tasked with completing issues on a gitlab repository. Please look at the open issues and complete them by creating merge requests that solve the issues.\"\n",
     ")"
    ]
   },