Remove 0.491 constant value from CPU die size

[tibosmn]

Fixes #275

In the current computation of CPU die size, we include a constant value of 0.491 cm², derived from Green Cloud Computing (Figure 31, where the precise value is 0.49157).

Given that we now utilize a die size derived from a more extensive range of CPU models than those examined in the referenced study, the addition of such a constant is unnecessary to the computation die size = die size per core * number of cores.

Consequently, I suggest setting constant_core_impact to 0 to easily handle this issue. Please advise if I should remove core_impact altogether.

[tibosmn]

To ease future maintainability I removed constant_core_impact and core_impact altogether.

Also updated the unit tests, sry 🤡

[da-ekchajzer]

I've fixed the conflict linked to updating unit tests in the PR : #272.

[demeringo]

Important

This change may slightly update the values of embedded impacts returned by he API (e.g. Boavizta/cloud-scanner#467)