ci: add weekly automated clippy autofix workflow

[SH20RAJ]

Adds a scheduled clippy autofix workflow with weekly and manual triggers.

Key behavior:

• captures pre-fix clippy output
• runs cargo clippy --fix and cargo fmt
• opens a PR only when changes are produced
• uses concurrency guard to avoid overlap

Closes #1047

[SH20RAJ]

Hi! Added a scheduled CI workflow that automatically fixes clippy warnings via PRs. This helps maintain high code quality standards across the repository asynchronously. (Fixes #1047)

[SH20RAJ]

Addressing Issue #1047. This PR introduces a scheduled GitHub Action to run cargo clippy --fix weekly. It automatically opens a PR with the suggested fixes, helping the team maintain high code quality standards across the entire MoFA workspace with minimal manual effort. 🤖