Fix vehicle parts being unrepairable after removing from vehicle (#79391

)

* fix vehicles parts repairability

* try fix clang tidy error

* accept gh bot suggestion

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

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Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

src/vehicle.cpp

@@ -8542,7 +8542,8 @@ item vehicle::part_to_item( const vehicle_part &vp ) const
 
     // quantize damage and degradation to the middle of each damage_level so that items will stack nicely
     tmp.set_damage( ( tmp.damage_level() - 0.5 ) * itype::damage_scale );
-    tmp.set_degradation( ( tmp.damage_level() - 0.5 ) * itype::damage_scale );
+    tmp.set_degradation( ( static_cast<double>( tmp.degradation() ) / itype::damage_scale - 0.5 ) *
+                         itype::damage_scale );
     return tmp;
 }