Fix hidden dock blocking clicks on X11

[sagar431]

Summary

Prevent the stationary outer dock container from contributing its full allocation to the X11 input region on GNOME Shell 4x.

When autohide slides the inner dash off-screen, the outer dashtodockContainer remains allocated across the bottom of the monitor. Since affectsInputRegion: false was removed during the GNOME 50 compatibility changes, that invisible allocation can continue intercepting clicks intended for maximized applications.

Change

Restore affectsInputRegion: false for the outer dock chrome actor, gated to GNOME Shell 4x using the same Config.PACKAGE_VERSION[0] == '4' pattern already used for the struts actor. GNOME 50 behavior is unchanged.

The separate reactive DockDwell actor remains intact, so edge reveal, pressure sensing, and the existing slide animation are unaffected.

Verification

• Reproduced on GNOME Shell 46.0, X11, with the dock at the bottom and autohide enabled.
• Before: controls near the bottom of a maximized application could not be clicked after the dock hid.
• After: those controls receive clicks while the dock is hidden.
• Verified that moving to the bottom hot zone still reveals the dock.
• Verified that hide/show and icon animations still work.
• node --input-type=module --check < dock.js passes.
• git diff --check passes.

This is a deliberately minimal version of the input-region fix discussed in #366.