Improve regex in @commitlint/load

[filipw01]

Description

1. Removed unnecessary case insensitivity flag
2. Removed unnecessary capturing group
3. Replaced String.match with RegExp.exec https://ota-meshi.github.io/eslint-plugin-regexp/rules/prefer-regexp-exec.html#regexp-prefer-regexp-exec

Motivation and Context

It slightly improves performance and removes redundancy

How Has This Been Tested?

It's a pretty local change, I just looked at it

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

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[escapedcat]

Thanks @filipw01 !

[escapedcat]

Damn, need to adjust the commit title :P