pyopenssl_signer: Use cryptography

[Javagedes]

per pyopenssl deprecation notice, the crypto module is being deprecated. Per the pyopenssl documentation, the cryptography module is the recommended replacement. This commit updates the pyopenssl_signer to use the cryptography module.

This deprecation was discovered as Ubuntu-24.04 images are missing the crypto module.

https://www.pyopenssl.org/en/stable/api/crypto.html

[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 78.79%. Comparing base (bf643b0) to head (cb4ef31).
Report is 120 commits behind head on master.

Files with missing lines	Patch %	Lines
edk2toolext/capsule/pyopenssl_signer.py	75.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #918      +/-   ##
==========================================
+ Coverage   78.75%   78.79%   +0.03%     
==========================================
  Files          49       41       -8     
  Lines        4909     5055     +146     
==========================================
+ Hits         3866     3983     +117     
- Misses       1043     1072      +29     

Files with missing lines	Coverage Δ
edk2toolext/capsule/pyopenssl_signer.py	69.04% <75.00%> (-2.01%)	⬇️

... and 48 files with indirect coverage changes