Eldarica version 2.3

The version of Eldarica from CHC-COMP 2026 (with some more minor changes after the competition).
Changes include:

• New bit-vector solver.
• Improved model generation, which should lead to significantly more compact solutions (options -sol and -ssol).
• Dropped support for parsing C programs, which is now provided by the separate tool TriCera.
• GraalVM for native images.