Regenerate multiline reference images + fix test_render_multiline spacing

The descender-aware line spacing change (A→Aj in getbbox) affects all
multiline text rendering output. This updates:

Reference images (16 files):
- multiline_text{,_center,_right,_justify,_justify_anchor}.png
- multiline_text_spacing.png
- test_anchor_multiline_{anchor}_{align}.png (11 files)

Test fix:
- test_render_multiline: use getbbox('Aj') to match new line spacing

All 212 tests in test_imagefont.py pass.

Tests/test_imagefont.py

@@ -223,7 +223,7 @@ def test_float_size(layout_engine: ImageFont.Layout) -> None:
 def test_render_multiline(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new(mode="RGB", size=(300, 100))
     draw = ImageDraw.Draw(im)
-    line_spacing = font.getbbox("A")[3] + 4
+    line_spacing = font.getbbox("Aj")[3] + 4
     lines = TEST_TEXT.split("\n")
     y: float = 0
     for line in lines: