ci: add job to check code format

[George-Miao]

No description provided.

[Copilot]

Pull Request Overview

This PR adds a new GitHub Actions workflow to enforce code formatting standards in the CI pipeline. The changes include the addition of a new workflow file and automatic formatting fixes to existing code, bringing them into compliance with the project's Rust formatting guidelines.

Key Changes

• Added a new GitHub Actions workflow (ci_format.yml) to check code formatting using cargo fmt
• Reformatted import statements and comments across multiple files to comply with formatting standards

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
.github/workflows/ci_format.yml	New CI workflow that runs cargo fmt --check on push/PR to master branch
compio-runtime/tests/drop.rs	Reorganized imports to place external crate imports after standard library imports
compio-runtime/src/runtime/scheduler/mod.rs	Reordered imports and reformatted multi-line comments to meet line length requirements
compio-fs/src/file.rs	Reformatted doc comment to comply with line length standards

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