Added pharo 13 to the CI

Author: jordanmontt

.github/workflows/CI.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       matrix:
         os: [ macos-latest, windows-latest, ubuntu-latest]
-        smalltalk: [ Pharo64-9.0, Pharo64-10, Pharo64-11, Pharo64-12 ]
+        smalltalk: [ Pharo64-9.0, Pharo64-10, Pharo64-11, Pharo64-12, Pharo64-13 ]
     runs-on: ${{ matrix.os }}
     name: ${{ matrix.smalltalk }}
     steps: