fix(iOS): align line height centering rounding with Android

Changed from ceil/floor to round with remainder calculation to
prevent 1-pixel vertical shifts and ensure cross-platform parity.

Author: ArekChr

packages/react-native/ReactCommon/react/renderer/textlayoutmanager/platform/ios/react/renderer/textlayoutmanager/RCTTextLayoutManager.mm

@@ -212,8 +212,8 @@ - (LinesMeasurements)getLinesForAttributedString:(facebook::react::AttributedStr
                                   CGFloat descender = fabs(font.descender);
                                   CGFloat textHeight = ascender + descender;
                                   CGFloat leading = usedRect.size.height - textHeight;
-                                  CGFloat adjustedAscender = ascender + ceil(leading / 2.0);
-                                  CGFloat adjustedDescender = descender + floor(leading / 2.0);
+                                  CGFloat adjustedAscender = ascender + round(leading / 2.0);
+                                  CGFloat adjustedDescender = descender + (leading - round(leading / 2.0));
                                   auto line = LineMeasurement{
                                       std::string([renderedString UTF8String]),
                                       rect,