Is authorizing a colleague to clock in and out on your behalf for a job that requires no more than that, in exchange for money, considered a bribe?

It is not permissible to deputize a colleague to sign on your behalf, whether for a fee or without, unless the company authorizes it. This is based on the Prophet's (peace be upon him) saying: "Muslims are bound by their conditions," and Allah Almighty's statement: "O you who have believed, fulfill [your] contracts." If the company does not authorize it, what the colleague takes is considered unlawful gain because it is in exchange for a prohibited benefit, and it is consuming wealth unjustly.