Bump requests dev dependency to resolve dependabot issue (#352)

## Problem

Dependabot opened PR #348 to bump our version of `requests`, which is
only used as a development dependency. Tests on that PR failed due to
the dependabot PR not being able to read secrets. This should resolve a
[moderate
severity](https://github.com/pinecone-io/pinecone-python-client/security/dependabot/17)
dependabot alert.

## Solution

- `poetry update requests`

## Type of Change

- [x] Bug fix (non-breaking change which fixes an issue)
- [x] None of the above: Dev-only security fix

## Test Plan

Tests should still pass.

Author: jhamon