Release v1.2.9

What's Changed

• Added Pharo 12 and 13 to CI
• BitmapCharacterSetTest>>#assertSet:copiedFrom:equals: should use isNotNil by @astares in #9

Full Changelog: v1.2.8...v1.2.9

v1.2.8

Cleanups, formatting, GitHub actions and Smalltalk CI

• Issue #2 - Cleanup: Remove ConfigurationOfBitmapCharacterSet
• Issue #5 - Remove BitmapCharacterSet class>>#inspectorClass
• Issue #7 - Add Github actions and use SmalltalkCI