feat: add ability to auto-instrument subprocesses

[herin049]

Description

Adds the ability to auto-instrument subprocesses via opentelemetry-instrument. This PR enables auto-instrumenting Uvicorn with multiple workers via:

opentelemetry-instrument --auto_instrumentation_instrument_subprocesses true uvicorn main:app --workers 4 --host 0.0.0.0 --port 8000

Fixes open-telemetry/opentelemetry-python#4927

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

uv run tox -e py312-test-opentelemetry-instrumentation-wrapt2

Does This PR Require a Core Repo Change?

• Yes. - Link to PR:
• No.

Checklist:

See contributing.md for styleguide, changelog guidelines, and more.

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[MikeGoldsmith]

Looks good - thanks @herin049. Need to move changelog.