feat: add retry on database connection

[jordanrfrazier]

DSLFv2 spins up a knative service running a langflow pod that immediately attempts to start in tandem while the database manager creates the appropriate tenant in the postgresql schema. Pods must give the database services time to create the tenant; this PR adds a short (and optional) retry on startup.

[codspeed-hq]

CodSpeed Performance Report

Merging #5772 will degrade performances by 33.07%

_{Comparing impl-db-retry (1e0d9ca) with main (88111c3)}

Summary

❌ 3 regressions
✅ 12 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	impl-db-retry	Change
❌	test_successful_run_with_input_type_any	262.2 ms	344 ms	-23.78%
❌	test_successful_run_with_input_type_text	175.5 ms	262.2 ms	-33.07%
❌	test_successful_run_with_output_type_debug	173.7 ms	254.3 ms	-31.73%