Deprecate usage of github token

[ynancher]

Remove dependency on GitHub API tokens by switching to local Git
commands for commit retrieval and validation. This change improves
security and simplifies the action's setup process.

With this change, the workflow will treat both private repos and public
repos similarly and will work in the same way for both.

[hasiburr-qti]

Looks, good,
One suggestion:

check-blank-line:
    required: false
    default: true
    description: "check for a blank line between commit title and body"

Here you are making default as boolean true, and in the check_commits.py file you are accepting default as string true, It would be better to maintain consistency.

[ynancher]

Looks, good, One suggestion:

check-blank-line:
    required: false
    default: true
    description: "check for a blank line between commit title and body"

Here you are making default as boolean true, and in the check_commits.py file you are accepting default as string true, It would be better to maintain consistency.

Thanks for pointing that out, have changed it to string by default to maintain consistency

[quic-vpendy]

can you update commit-msg of this PR to provide more information on this change like why this is needed etc?

[abinjose-qualcomm]

I see same changes being added/reverted between the two commits. Can you squash your changes? Or separate the changes logically in separate commits.