v1/charm_tracing.py library raises Exception on import opentelemetry due to stale packages

[ca-scribner]

Bug Description

#151 attempts to address an issue where., during charm refresh, some opentelemetry tooling raises an Exception because empty leftover package directories are left in the virtual environment. #151 focued on applying the patch from within a decorator in the library, and only on the opentelemetry_sdk package.

It turns out that this problem can also occur:

• for other opentelemetry packages (specifically noticed for opentelemetry_api)
• at import time, eg when doing import opentelemetry, because opentelemetry/context/__init__.py does a similar inspection of packages

This means that the patch from #151 is too narrow (should apply to opentelemetry_*) and too late (must be done before importing any opentelemetry package)

To Reproduce

(in a machine model)

to repro the original issue

charmcraft pack
juju deploy grafana-agent --revision=134 --channel=latest/stable
juju deploy ubuntu
juju relate grafana-agent ubuntu
# wait for deploy to finish and charm to go to blocked (because it has no target for its metrics)

# rebuild grafana-agent latest/edge with v12 (old) version of the library
juju refresh grafana-agent --path ./grafana-agent_ubuntu-22.04-amd64.charm

juju refresh grafana-agent --channel latest/edge
# charm should refresh and go to error

Environment

Relevant log output

-

Additional context

No response