4.0.0

What's Changed

• Remove class for UTC compat for Python 2 by @daveisfera in #338
• Use built-in ISO 8601 parse for Python 3.11 and later by @daveisfera in #336
• Run pyupgrade for 3.7 by @daveisfera in #339
• Upgrade actions to latest stable version by @daveisfera in #335
• Add 3.12 to the list of versions to test by @daveisfera in #334
• Pass timespec all the way down in dumps by @daveisfera in #345
• Ruff cleanup by @daveisfera in #337
• Run format with ruff by @daveisfera in #346

Full Changelog: 3.6.0...4.0.0