CI: run pytest and install test against Python 3.10

Use Alpine 3.17 to test pmbootstrap with older versions of Python

Fixes: #2477 (closed)

pmb/core/chroot.py

@@ -50,9 +50,6 @@ class Chroot:
             "riscv64",
         ]
 
-        if self.__type not in ChrootType:
-            raise ValueError(f"Invalid chroot type: '{self.__type}'")
-
         # A buildroot suffix must have a name matching one of alpines
         # architectures.
         if self.__type == ChrootType.BUILDROOT and self.__name not in valid_arches: