feat: add support for capture_parameters to Psycopg2Instrumentor

[gregoiredx]

Description

Add support for dbapi capture_parameters param to Psycopg2Instrumentor.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

I used a similar change on our stack, here is the result as seen in Grafana

Does This PR Require a Core Repo Change?

• 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]

Thanks for the contribution @gregoiredx 🚀

capture_parameters is already exposed in psycopg, aiopg, asyncpg, and tortoiseorm using the same underlying db.statement.parameters attribute, so this is consistent with the existing pattern in the repo.

However, it's worth noting the current attribute name (db.statement.parameters) and format (stringified tuple) diverges from the latest OTel semconv, which defines db.query.parameter.<key>] as individual per-parameter attributes (e.g. db.query.parameter.0, db.query.parameter.1, etc), with db.statement deprecated in favour of db.query. This PR doesn't introduce that problem though — it's pre-existing across all dbapi-based instrumentations.

Related issues:

• #2929 for dbapi
• #2678 for psycopg2

[tammy-baylis-swi]

Thanks for this! A few suggestions:

Please do tox -e lint-instrumentation-psycopg2 and commit format/style changes, since we're still using both pylint and ruff.

Please also update test_psycopg2_integration.py to assert span attributes with the memory exporter, similar to the psycopg(3) PR.