ADAP-1183: Use the new location for dbt-postgres

[emmyoop]

Problem

dbt-postgres is moving to dbt-adapters.

Solution

Change links.

blocked on dbt-labs/dbt-adapters#615

Checklist

• I have read the contributing guide and understand what's expected of me.
• I have run this code in development, and it appears to resolve the stated issue.
• This PR includes tests, or tests are not required or relevant for this PR.
• This PR has no interface changes (e.g., macros, CLI, logs, JSON artifacts, config files, adapter interface, etc.) or this PR has already received feedback and approval from Product or DX.
• This PR includes type annotations for new and modified functions.

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change. For details on how to document a change, see the contributing guide.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.88%. Comparing base (31881d2) to head (cfb0d86).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #11234      +/-   ##
==========================================
- Coverage   88.93%   88.88%   -0.06%     
==========================================
  Files         187      187              
  Lines       24049    24049              
==========================================
- Hits        21388    21375      -13     
- Misses       2661     2674      +13     

Flag	Coverage Δ
integration	86.19% <ø> (-0.14%)	⬇️
unit	62.47% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
Unit Tests	62.47% <ø> (ø)
Integration Tests	86.19% <ø> (-0.14%)	⬇️