Bump version 0.2.1

[TheoLaudatQM]

Added

• Add TwoQubitExperimentNodeParameters class
• New dependencies: lmfit, matplotlib, numpy, qm, quam-builder, qualibrate, scipy, xarray
• Test suite (using pytest) with 39 tests covering exception handling and core functionality
• Github action that runs the test suite during pull request workflows

Changed

• Enhanced exception messages throughout the library to provide more helpful context
• Updated BatchableList.repr method to show batch configuration
• Updated analysis modules : extracted qiskit-experiment guess.py into package.

Removed

• Removed qiskit-experiment dependency