Remove Equinor-specific requirements from the FOSS package

[kwinkunks]

There are hardcoded business rules in the package, e.g. see #308, #309 and #310. In the case of matrix requirements (Python and RHEL versions in our case), these appear in both the matrix generating code (release_transpiler.py and matrix.py) and in the linter (lint.py).

Assuming #308 deals with that specific case, we should scour the code for other examples. For example, in the code there are:

• 17 mentions of "equinor"
• 16 mentions of "rhel" or "rh"
• 55 mentions of "python", some of which are probably legit

[kwinkunks]

See also #316