Add alloydb vector search codeowners

[vinay0410]

Description

Fixes #

Checklist

Testing

• I have tested this change on a live environment and verified it works as intended.

Compliance & Style

• I have followed the Sample Guidelines.
• The README is updated with all relevant information (if applicable).
• If this PR adds a new sample directory: I updated the CODEOWNERS file.

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Post-Approval Actions

• Please merge this PR for me once it is approved

[gemini-code-assist]

Code Review

This pull request adds the alloydb-vector-search-docs team to the CODEOWNERS file for the alloydb directory and introduces a new test, test_alloydb_vector_search_benchmark, in alloydb/notebooks/e2e_test.py to run a benchmark notebook with reduced parameters. Feedback suggests making the new test synchronous as it lacks asynchronous operations, and using repr(password) instead of string interpolation to safely handle special characters in passwords.

[gemini-code-assist]

The test function test_alloydb_vector_search_benchmark is defined as an asynchronous function (async def) and decorated with @pytest.mark.asyncio, but it does not contain any await expressions or asynchronous operations. Making it synchronous simplifies the test and avoids unnecessary async overhead.

Additionally, using f"db_pass = '{password}'" can cause syntax errors or test failures if the password contains single quotes or backslashes. Using repr(password) is safer and more robust as it automatically handles escaping and quotes.

def test_alloydb_vector_search_benchmark(
    project_id: str,
    cluster_name: str,
    instance_name: str,
    region: str,
    database_name: str,
    password: str,
) -> None:
    # Run the benchmark notebook with significantly reduced parameters
    # to allow CI to complete quickly without OOMs or timeouts
    conftest.run_notebook(
        "alloydb_vector_search_benchmark.ipynb",
        variables={
            "project_id": project_id,
            "region": region,
            "cluster_id": cluster_name,
            "instance_id": instance_name,
            "db_name": database_name,
            "db_user": "postgres",
            "test_queries": 10,
        },
        preprocess=preprocess,
        skip_shell_commands=True,
        replace={
            (
                "db_pass = getpass.getpass("
                '"🔑 Enter Database Password for AlloyDB: ")'
            ): f"db_pass = {repr(password)}",
            "train_data = f['train'][:]": "train_data = f['train'][:1000]",
            "test_data = f['test'][:]": "test_data = f['test'][:100]",
            "neighbors_data = f['neighbors'][:]": (
                "neighbors_data = f['neighbors'][:100]"
            ),
            "ef_values = [40, 100, 200, 400, 800]": "ef_values = [40]",
        },
        until_end=True,
    )