4.4.0

What's Changed

• asdftool fixes by @braingram in #1939
• Port benchmarks to pytest-benchmark, enable codspeed by @braingram in #1943
• add asdftool validate by @braingram in #1952
• Bump actions/checkout from 4 to 5 by @dependabot[bot] in #1954
• Simplify open by @braingram in #1955
• Check for external pytest-asdf-plugin and don't register bundled plugin if the external one exists by @braingram in #1957
• update changelog for 4.4.0 by @braingram in #1958

Full Changelog: 4.3.0...4.4.0