0.3.1

What's Changed

• build(deps): bump actions/checkout from 5 to 6 by @dependabot[bot] in #131
• Drop support for Python 3.9 by @caleb-johnson in #142
• Fix linter errors by @caleb-johnson in #143
• Drop support for Python 3.9, part 2 by @garrison in #144
• Bump Python version for cov testing to 3.11 by @caleb-johnson in #149
• build(deps): bump actions/upload-artifact from 5 to 6 by @dependabot[bot] in #136
• build(deps-dev): bump mypy from 1.18.2 to 1.19.1 by @dependabot[bot] in #137
• build(deps-dev): bump pylint from 3.3.9 to 4.0.5 by @dependabot[bot] in #147
• build(deps-dev): bump ruff from 0.12.11 to 0.15.4 by @dependabot[bot] in #146
• add exp_val basic tests by @dekelmeirom in #141
• Expectation-value indexing bugfix by @aeddins-ibm in #145
• Bump version to 0.3.1 by @caleb-johnson in #150

Full Changelog: 0.3.0...0.3.1