fix: update vector RAG flow for Astra DB comp changes

[erichare]

This pull request updates the Vector Store RAG template for changes that have been made to the Astra DB Component.

[Cristhianzl]

lgtm

[codspeed-hq]

CodSpeed Performance Report

Merging #5006 will degrade performances by 23.56%

_{Comparing bugfix-vector-rag-starter (02f43dc) with main (19d2974)}

Summary

⚡ 2 improvements
❌ 1 regressions
✅ 12 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	bugfix-vector-rag-starter	Change
⚡	test_successful_run_with_input_type_any	325.1 ms	233.4 ms	+39.28%
❌	test_successful_run_with_output_type_any	189.9 ms	248.4 ms	-23.56%
⚡	test_successful_run_with_output_type_debug	232.3 ms	141.2 ms	+64.5%