Add support for list, describe, and delete namespace

[rohanshah18]

Problem

Add support for list, describe, and delete namespaces.

Solution

Generated code using 2025-04 protos and added the following methods for namespaces for both index and asyncIndex:

1. listNamespaces()
2. listNamespaces(String paginationToken)
3. listNamespaces(String paginationToken, int limit)
4. describeNamespace(String namespace)
5. deleteNamespace(String namespace)

Following example shows listNamespaces(), describeNamespace(), and deleteNamespace() methods for both index and asyncIndex.

import io.pinecone.clients.AsyncIndex;
import io.pinecone.clients.Index;
import io.pinecone.clients.Pinecone;
import io.pinecone.proto.ListNamespacesResponse;
import io.pinecone.proto.NamespaceDescription;

import java.util.concurrent.ExecutionException;
...

String indexName = "PINECONE_INDEX_NAME";
Pinecone pinecone = new Pinecone.Builder("PINECONE_API_KEY").build();

//// Sync index example
Index index = pinecone.getIndexConnection(indexName);

// list namespaces without pagination token and limit (if no limit is passed, it'll default to 100)
ListNamespacesResponse listNamespacesResponse = index.listNamespaces();

// list namespaces with pagination token
listNamespacesResponse = index.listNamespaces("some-pagination-token");

// list namespaces with pagination token and a custom limit of 5
listNamespacesResponse = index.listNamespaces("some-pagination-token", 5);

// describe a namespace
NamespaceDescription namespaceDescription = index.describeNamespace("namespace");

// delete a namespace
index.deleteNamespace("namespace");


//// AsyncIndex example
AsyncIndex asyncIndex = pinecone.getAsyncIndexConnection(indexName);

// list namespaces without pagination token and limit (if no limit is passed, it'll default to 100)
ListNamespacesResponse asyncListNamespacesResponse = index.listNamespaces();

// list namespaces with pagination token
asyncListNamespacesResponse = asyncIndex.listNamespaces("some-pagination-token").get();

// list namespaces with pagination token and a custom limit of 5
asyncListNamespacesResponse = asyncIndex.listNamespaces("some-pagination-token", 5).get();

// describe a namespace
NamespaceDescription asyncNamespaceDescription = asyncIndex.describeNamespace("some-namespace").get();

// delete a namespace
asyncIndex.deleteNamespace("some-namespace");

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Infrastructure change (CI configs, etc)
• Non-code change (docs, etc)
• None of the above: (explain here)

Test Plan

Added integration tests.

[austin-denoble]

LGTM 🚢