US_Texas_Diabetes - added download.py

[goutamabrol]

import name - US_Texas_Diabetes

PR checklist - Doc

Summary of Changes

• Source is changed because previous source url was not accessable due to geographic restrictions.
• Created download.py script to download the data from source.
• Created pvmap in accordance with the new source data.
• Updated manifest which was pointing towards wrong directories.
• Updated README.md with correct steps.
• validation_output from test run - link

[gemini-code-assist]

Code Review

This pull request automates the ingestion of Texas diabetes mortality data by introducing a download script (download.py) for CDC WONDER, updating the PV mapping file, and revising the workflow documentation. Feedback focuses on correcting a configuration filename mismatch in manifest.json, increasing the download retry limit to handle external source instability, and updating the provenance description to consistently reference CDC WONDER.