PG19: handle property graph dependency object classes

[ibrahim halatci (ihalatci)]

Summary

• recognize PostgreSQL 19 property-graph label and property object classes in the compatibility mapper
• keep property-graph objects on Citus's safe unsupported-dependency path
• gate the new catalogs and mappings to PostgreSQL 19+

Validation

• PostgreSQL 19beta2: clean build and targeted privileges regression pass; original object-class 6470/6473 errors no longer reproduce
• PostgreSQL 17.10: all 225 vanilla tests pass
• PostgreSQL 18.4: all 231 vanilla tests pass

Fixes #8729

Fixes #8729.

Upstream provenance

The property-graph catalogs and relation OIDs 6470/6473 predate PG19 Beta1. Beta2-range PostgreSQL commit 9d8cdcbe0c8a began recording graph-label/property dependencies, which exposed those pre-existing ObjectAddress.classId values to Citus and triggered the stale compatibility mapper. Thus the omission was latent in Beta1 and directly exposed by Beta2 dependency behavior.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.80%. Comparing base (ff8f1f8) to head (b73e5f6).

Additional details and impacted files

@@               Coverage Diff                @@
##           pg19-support    #8733      +/-   ##
================================================
- Coverage         88.80%   88.80%   -0.01%     
================================================
  Files               288      288              
  Lines             64416    64420       +4     
  Branches           8100     8102       +2     
================================================
+ Hits              57206    57208       +2     
- Misses             4873     4875       +2     
  Partials           2337     2337              

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.