Prepare to release Java SDK v4.0.0 (#176)

## Problem

Prepare to release Java SDK v4.0.0.

## Solution

Releasing a major version requires updating:
1. README
2. gradle.properties
3. CHANGELOG.md
4. Constants.java


## 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)
- [X] Non-code change (docs, etc)
- [ ] None of the above: (explain here)

## Test Plan

NA

Author: rohanshah18

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 [comment]: <> (When bumping [pc:VERSION_LATEST_RELEASE] create a new entry below)
 ### Unreleased version
+### 4.0.0
+- Add support for sparse indexes
+- Generate code based on 2025-01 open-api spec
+
 ### 3.1.0
 - Add support to pass base url for control and data plane operations
 

LICENSE

@@ -186,7 +186,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright [yyyy] [name of copyright owner]
+   Copyright 2023 Pinecone Systems, Inc.
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

README.md

@@ -15,20 +15,20 @@ Maven:
 <dependency>
   <groupId>io.pinecone</groupId>
   <artifactId>pinecone-client</artifactId>
-  <version>3.0.0</version>
+  <version>4.0.0</version>
 </dependency>
 ```
 
 [comment]: <> (^ [pc:VERSION_LATEST_RELEASE])
 
 Gradle:
 ```
-implementation "io.pinecone:pinecone-client:3.0.0"
+implementation "io.pinecone:pinecone-client:4.0.0"
 ```
 
 [comment]: <> (^ [pc:VERSION_LATEST_RELEASE])
 
-Alternatively, you can use our standalone uberjar [pinecone-client-3.0.0-all.jar](https://repo1.maven.org/maven2/io/pinecone/pinecone-client/3.0.0/pinecone-client-3.0.0-all.jar), which bundles the Pinecone
+Alternatively, you can use our standalone uberjar [pinecone-client-4.0.0-all.jar](https://repo1.maven.org/maven2/io/pinecone/pinecone-client/4.0.0/pinecone-client-4.0.0-all.jar), which bundles the Pinecone
 SDK and all dependencies together. You can include this in your classpath like you do with any 3rd party JAR without
 having to obtain the *pinecone-client* dependencies separately.
 
@@ -202,7 +202,6 @@ import java.util.HashMap;
 Pinecone pinecone = new Pinecone.Builder("PINECONE_API_KEY").build();
 
 String indexName = "example-index";
-int dimension = 1538;
 String cloud = "aws";
 String region = "us-east-1";
 HashMap<String, String> tags = new HashMap<>();

gradle.properties

@@ -1 +1 @@
-pineconeClientVersion = 3.1.0
+pineconeClientVersion = 4.0.0

src/main/java/io/pinecone/commons/Constants.java

@@ -1,5 +1,5 @@
 package io.pinecone.commons;
 
 public class Constants {
-    public static final String pineconeClientVersion = "v3.1.0";
+    public static final String pineconeClientVersion = "v4.0.0";
 }