Improvement: Error handling for malformed config files in check-hooks-installed.py and check_cargo_lints.py

[sharanammahosur96]

Description

Both pre-commit-action/check-hooks-installed.py and shared-lints/check_cargo_lints.py assume their input files are well-formed. If a config file is malformed, the scripts raise unhandled exceptions instead of a clean failure message.

Motivation

Why is this change needed?
What is the benefit to users, maintainers, or performance?

Contributors fixing their .pre-commit-config.yaml or Cargo.toml should get a message that tells them what's wrong with their file, not an internal traceback.
This also makes failures easier to triage from CI logs alone.

Proposed Solution

• Wrap the YAML/TOML parsing calls in try/except
• On parse failure, print a clear [FAIL] message (consistent with existing output style) identifying which file failed and why, then exit 1
• Add/extend test coverage for malformed-input cases

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Additional Context

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Important

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