fix(deps): Downgrade pytest to 8.3.5 for syrupy compatibility

syrupy 4.8.1 requires pytest<9.0.0, so downgrade from 9.0.1 to 8.3.5.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: Nik Samokhvalov

reporter/requirements-dev.txt

@@ -1,5 +1,5 @@
 -r requirements.txt
-pytest==9.0.1
+pytest==8.3.5
 pytest-postgresql==7.0.2
 coverage==7.6.10
 pytest-cov==6.0.0