Remove some unnecessary None checks from desktop profile code

[correctmost]

PR Description:

This commit fixes some warnings reported by Pyright's reportUnnecessaryComparison checker:

archinstall/archinstall/default_profiles/desktops/hyprland.py:69:7 - error: Condition will always evaluate to True since the types "MenuItem" and "None" have no overlap (reportUnnecessaryComparison)
archinstall/archinstall/default_profiles/desktops/labwc.py:66:7 - error: Condition will always evaluate to True since the types "MenuItem" and "None" have no overlap (reportUnnecessaryComparison)
archinstall/archinstall/default_profiles/desktops/niri.py:74:7 - error: Condition will always evaluate to True since the types "MenuItem" and "None" have no overlap (reportUnnecessaryComparison)
archinstall/archinstall/default_profiles/desktops/sway.py:76:7 - error: Condition will always evaluate to True since the types "MenuItem" and "None" have no overlap (reportUnnecessaryComparison)

Tests and Checks

• I have tested the code!