v1.9.0 Release: Bugfix and Dependency Update

What's Changed

• Bump actions/checkout from 2 to 3 by @dependabot in #64
• Bump extern/pybind11 from f495dfc to 465b2e0 by @dependabot in #63
• Bump extern/dd_package from 0333030 to 2345841 by @dependabot in #67
• Bump extern/json from e4643d1 to 700b95f by @dependabot in #65
• Bump extern/pybind11 from 465b2e0 to 2dd5254 by @dependabot in #66
• Bump extern/pybind11 from 2dd5254 to f8a532a by @dependabot in #69
• Bump extern/dd_package from 2345841 to 03f72e2 by @dependabot in #70
• Bump extern/pybind11 from f8a532a to b22ee64 by @dependabot in #71
• Bump extern/dd_package from 03f72e2 to 65f6287 by @dependabot in #72
• ✨Equality checks for Operations by @burgholzer in #73
• Bugfixes for QCEC by @burgholzer in #74

Full Changelog: v1.8.0...v1.9.0