Release 0.6.0

What's Changed

• feat: add soft assertions with expect_all by @DamianReeves in #57
• feat: support more collection types by @DamianReeves in #58
• feat: add for_all for property-based tests by @DamianReeves in #59
• feat: add failure_message and expect_failure for testing matchers by @DamianReeves in #60
• feat: add eventually for async code by @DamianReeves in #61
• docs: explain snapshot testing with MoonBit's own tools by @DamianReeves in #62
• feat: add with_source to show the expression under test by @DamianReeves in #63
• chore: release 0.6.0 by @DamianReeves in #64

Full Changelog: v0.5.0...v0.6.0