According to the principles of special relativity, the speed of light is the maximum speed at which information can propagate in the universe. Therefore, even though the rockets are traveling toward each other at the speed of light, they cannot "see" each other instantaneously.
Let's consider an observer on Rocket A. The observer on Rocket A will see light emitted from Rocket B taking one year to reach them since they are one light-year apart. This is because the speed of light is the same for all observers, regardless of their relative velocities. Similarly, an observer on Rocket B will see light emitted from Rocket A taking one year to reach them.
Therefore, each rocket will "see" the other rocket exactly one year after they emitted the light. This means that they will observe each other at the same relative speed at which they are approaching, which is the speed of light.
It is important to note that this scenario involves speeds that approach the theoretical maximum allowed by special relativity, which is the speed of light. In reality, objects with mass cannot reach or exceed the speed of light. However, for the sake of this hypothetical scenario, we assume that the rockets are traveling at the speed of light.