Bump dependencies (#365)

## Problem

Dependabot has flagged several out of date dependency versions but the
integration tests can't run on those PRs due to security limits imposed
by github.

## Solution

Run `poetry update certifi pdoc urllib3` to update poetry.lock with
up-to-date dependencies.

## Type of Change

- [x] None of the above: Chore, security updates

## Test Plan

Should see tests still passing.