fix: Update dependabot.yml path

[Roopan-Microsoft]

Purpose

• This pull request includes a change to the .github/dependabot.yml file to update the directory path for backend dependencies managed by Dependabot.

• .github/dependabot.yml: Changed the directory for the pip package-ecosystem from /src/backend to /src.

Does this introduce a breaking change?

• Yes
• No

Golden Path Validation

• I have tested the primary workflows (the "golden path") to ensure they function correctly without errors.

Deployment Validation

• I have validated the deployment process successfully and all services are running as expected with this change.

What to Check

Verify that the following are valid

• I have built and tested the code locally and in a deployed app
• For frontend changes, I have pulled the latest code from main, built the frontend, and committed all static files.
• This is a change for all users of this app. No code or asset is specific to my use case or my organization.

Other Information