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

@@ -50,6 +50,9 @@ class Chroot:
             "riscv64",
         ]
 
+        if self.__type not in ChrootType._member_map_.values():
+            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: