Refactor bit manipulation and remove myhdl dependency

[fsagbuya]

Hi, we are planning to use linien on our lab. Would like to propose some helpful updates for the pyp3 package.

This PR focuses on:

• replacing the few instances of intbv from myhdl with native Python bitwise operations;
• and removing the myhdl dependency from the project setup.

Given that intbv is utilized sparingly within the code, continuing to include myhdl as a dependency seems unnecessary and could potentially bloat the package.

Kindly requesting a review of these changes to validate the improvements and ensure no unintended side effects have been introduced. Your insights and approval would be greatly appreciated.

[bleykauf]

Thanks for your PR, removing the myhdl dependency is a welcome change. I merged and released as part of version v2.1.0.