Update `go.mod` to support v4.0.0 major version update #426

	name: ci
	on:
	pull_request: {}

	jobs:
	build:
	runs-on: ubuntu-latest
	services:
	pc-index-serverless:
	image: ghcr.io/pinecone-io/pinecone-index:latest
	ports:
	- 5081:5081
	env:
	PORT: 5081
	DIMENSION: 1536
	METRIC: dotproduct
	INDEX_TYPE: serverless
	pc-index-pod:
	image: ghcr.io/pinecone-io/pinecone-index:latest
	ports:
	- 5082:5082
	env:
	PORT: 5082
	DIMENSION: 1536
	METRIC: cosine
	INDEX_TYPE: pod
	steps:
	- uses: actions/checkout@v4
	- name: Setup Go
	uses: actions/setup-go@v5
	with:
	go-version: "1.21.x"
	- name: Install dependencies
	run: \|
	go get ./pinecone
	- name: Run tests
	run: go test -count=1 -v ./pinecone
	env:
	PINECONE_API_KEY: ${{ secrets.API_KEY }}
	- name: Run local integration tests
	run: go test -count=1 -v ./pinecone -run TestRunLocalIntegrationSuite -tags=localServer
	env:
	PINECONE_INDEX_URL_POD: http://localhost:5082
	PINECONE_INDEX_URL_SERVERLESS: http://localhost:5081
	PINECONE_DIMENSION: 1536

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