Pin to newer version of poetry, and cleanup package pinning

[devinmatte]

Motivation

People have been using various versions of poetry, each which generates a different lockfile. This should ensure everyone is using a newer version, leading to less lockfile issues

Changes

• Pins poetry to use something greater than poetry core 1.5.0
• Updates lockfile with latest poetry version
• Pins ddtrace to 1.15.0 until datadog fixes its size (ddtrace adding cmake as dependency balloons package size DataDog/datadog-lambda-python#349)
• Updates black and runs black formatting
• Pins botocore so it doesn't get out of step with boto3

Testing Instructions

Run poetry self update

If the above fails, then uninstall old versions of poetry, then install from scratch using docs https://python-poetry.org/docs/

[devinmatte]

Running in Beta now

[mathcolo]

Awesome, thanks!!