Enable GitHub CI builds against OpenSSL `master`

[VladGud]

Enable GitHub CI builds against OpenSSL master

Goal

Add GitHub Actions workflow to build and test gost-engine against OpenSSL master branch to ensure compatibility with upcoming OpenSSL releases and validate removal of deprecated APIs.

Tasks

1. Update workflows to add a new job (or matrix configuration) that:

   • Clones and builds OpenSSL from master branch
   • Builds gost-engine against this OpenSSL version
   • Runs test suite

2. Add OPENSSL_NO_DEPRECATED_3_0 build:

   • Configure OpenSSL with -DOPENSSL_NO_DEPRECATED_3_0
   • Ensures all deprecated 3.0 APIs have been eliminated from the codebase

Success Criteria

• CI successfully builds against OpenSSL master
• Build succeeds with OPENSSL_NO_DEPRECATED_3_0 defined
• All tests pass on both configurations

Context

This serves as final validation that all deprecated APIs removed in previous refactoring issues have been completely eliminated from the codebase.