We need to fix the way the processors are counted

[timlinux]

Problem

As reported by @ThomasG77 there is code duplication for counting the number of processors available on the system.

Proposed solution

• Refactor all implemetations of logic for counting processors into a single universal helper function.
• Ensure there is no regression to the fix in #12

Expected outcome

There should be a single point of truth for performing CPU counts.