chore: Bump test fixtures to use PG18 - BED-8581

[StephenHinck]

Description

Updates test fixtures to utilize PG18 alongside the fleet.

Resolves: BED-8581

Type of Change

• Chore (a change that does not modify the application functionality)
• Bug fix (a change that fixes an issue)
• New feature / enhancement (a change that adds new functionality)
• Refactor (no behaviour change)
• Test coverage
• Build / CI / tooling
• Documentation

Testing

• Unit tests added / updated
• Integration tests added / updated
• Full test suite run (make test_all with CONNECTION_STRING set)

Screenshots (if appropriate):

Driver Impact

• PostgreSQL driver (drivers/pg)
• Neo4j driver (drivers/neo4j)

Checklist

• Code is formatted
• All existing tests pass
• go.mod / go.sum are up to date if dependencies changed

Summary by CodeRabbit

• Chores
  • Upgraded PostgreSQL from version 16 to 18 across testing and development environments
  • Updated development configuration to ignore macOS system files

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 40e0f929-79bd-43a3-82aa-5a7199d053b5

📥 Commits

Reviewing files that changed from the base of the PR and between a637b4a and 6fd5c93.

📒 Files selected for processing (3)

• .github/workflows/go-test.yml
• .gitignore
• docker-compose.yml

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Walkthrough

This PR updates the development and test infrastructure to PostgreSQL 18, replacing the existing PostgreSQL 16 setup across GitHub Actions and Docker Compose configurations. The volume mount path for PostgreSQL data storage is also adjusted. A minor cleanup entry for macOS files is added to gitignore.

Changes

Infrastructure and Configuration Updates

Layer / File(s)	Summary
PostgreSQL 16 to 18 upgrade .github/workflows/go-test.yml, docker-compose.yml	PostgreSQL service image is bumped from postgres:16 to postgres:18 in the integration test workflow and Docker Compose. The Docker Compose volume mount path is adjusted from /var/lib/postgresql/data to /var/lib/postgresql.
Development environment cleanup .gitignore	macOS .DS_Store file is added to the gitignore list.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Suggested reviewers

• zinic
• superlinkx

Poem

🐰 Postgres climbs from sweet sixteen to eighteen bright,
Volumes shift their paths to hold the data right,
And .DS_Store now hides from sight,
The warren's infra gleams with cleaner light! ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically describes the main change: upgrading test fixtures from PostgreSQL 16 to 18, with ticket reference.
Description check	✅ Passed	The description follows the template structure with all required sections completed: description, type of change (chore selected), testing (full test suite run checked), and checklist items confirmed.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch BED-8581

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