Remove redundant GC.dispose() calls for Image

This minor refactoring eliminates unnecessary calls to GC.dispose() since disposing an Image automatically disposes its associated GC. There is no visual impact from this change.

Author: arunjose696

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/Image.java

@@ -2831,7 +2831,6 @@ private ImageData loadImageData(ZoomContext zoomContext) {
 			drawer.postProcess(imageData);
 			return adaptImageDataIfDisabledOrGray(imageData);
 		} finally {
-			gc.dispose();
 			image.dispose();
 		}
 	}

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Composite.java

@@ -1635,7 +1635,6 @@ LRESULT WM_PAINT (long wParam, long lParam) {
 						GCData gcData = gc.getGCData ();
 						if (gcData.focusDrawn && !isDisposed ()) updateUIState ();
 					}
-					gc.dispose();
 					if (!isDisposed ()) {
 						paintGC.drawImage (image, DPIUtil.pixelToPoint(ps.left, zoom), DPIUtil.pixelToPoint(ps.top, zoom));
 					}