Add changelog entry.

[peterallenwebb]

Resolves #10235

Problem

dbt-core needs new config schema for the hard_deletes mode.

Solution

Add hard_deletes property to snapshot schema objects.

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.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.84%. Comparing base (6b5db17) to head (493381a).
Report is 10 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10972      +/-   ##
==========================================
- Coverage   89.17%   85.84%   -3.33%     
==========================================
  Files         183      183              
  Lines       23491    23554      +63     
==========================================
- Hits        20947    20219     -728     
- Misses       2544     3335     +791     

Flag	Coverage Δ
integration	82.56% <100.00%> (-3.90%)	⬇️
unit	62.76% <100.00%> (+0.68%)	⬆️

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Components	Coverage Δ
Unit Tests	62.76% <100.00%> (+0.68%)	⬆️
Integration Tests	82.56% <100.00%> (-3.90%)	⬇️