FLATPAK Package does not properly respond to `any` value for OS/ARCH

[hollowaykeanho]

Description

When the target OS/ARCH is having any value, the FLATPAK packager refused to package (incompatible candidate). It's likely due to mishap in safety checking.

Expected Behavior

FLATPAK packager allows any target OS and target ARCH value.

Current Behavior

FLATPAK packager rejects any value for both target's OS and target's ARCH.

Steps to Reproduce [COMPULSORY]

1. build a polygot shell script that offers to any OS and any ARCH functionalities.
2. run the CI. notice that .flatpak is not packaged due to incompatible type.

Associated Data Files

No response