build: drop shortened URL from lint-commit-message

The shortened link to the commit message guidelines no longer works after they were moved from docs/guides to docs/contributing. Now that core-validate-commit outputs an error message pointing to the full URL of the commit message guidelines on failure we no longer need to include the URL (shortened or otherwise) in the workflow title.

Refs: https://github.com/nodejs/core-validate-commit/pull/95 Refs: https://github.com/nodejs/node/issues/41697

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As an example,

• Before https://github.com/nodejs/core-validate-commit/pull/95: https://github.com/nodejs/node/runs/5355414643?check_suite_focus=true
• After https://github.com/nodejs/core-validate-commit/pull/95: https://github.com/nodejs/node/runs/5377503722?check_suite_focus=true The https://github.com/nodejs/node/blob/HEAD/doc/contributing/pull-requests.md#commit-message-guidelines link in the job output is clickable.