Switch to Capstone with paired-singles support

[riptl]

I've recently added paired-singles support to Capstone in https://github.com/capstone-engine/capstone/pull/1898 and https://github.com/capstone-engine/capstone/pull/1900.

This means we can finally remove some doldisasm wrapper hacks.

It would take too long to wait for a new Capstone release so I've updated pip requirements to point to the latest Capstone v5 commit. pip install -r requirements.txt will work as before but now compiles Capstone from source instead of using a binary from PyPI.

• [x] Remove doldisasm wrappers
• [x] Update py requirements
• [x] Add C compiler to CI
• [x] Test locally