fix: Update PsycopgInstrumentor.instrument_connection to use async cursor factory

[dspatoulas]

Description

Update PsycopgInstrumentor.instrument_connection to support both sync and async psycopg connections by configuring the appropriate cursor_factory.

Previously, instrument_connection always used the sync cursor factory and did not properly handle AsyncConnection instances. As a result, calls made through an async connection would fail because of the async context.

With this change:

• If connection is a psycopg.AsyncConnection, we set connection.cursor_factory to _new_cursor_async_factory(...).
• Otherwise, we set connection.cursor_factory to _new_cursor_factory(...).

This aligns instrument_connection with the behavior of the global instrument() helper and ensures both sync and async connections are correctly traced.

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?

The tests in the psycopg instrumentation test suite to already cover both sync and async connections.

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

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: dspatoulas / name: DJ Spatoulas (4464519, e2ff5af)

[herin049]

Can we add some unit tests to cover this scenario? Also make sure to add a changelog entry.

[dspatoulas]

Can we add some unit tests to cover this scenario? Also make sure to add a changelog entry.

Yup, updated the existing tests and added a new test for this change.