Remove old multicol tests that were only run with the old implementation.

LayoutTests/virtual/slimmingpaint/fast/multicol/span/before-child-anonymous-column-block-expected.txt

Index: LayoutTests/virtual/slimmingpaint/fast/multicol/span/before-child-anonymous-column-block-expected.txt
diff --git a/LayoutTests/virtual/slimmingpaint/fast/multicol/span/before-child-anonymous-column-block-expected.txt b/LayoutTests/virtual/slimmingpaint/fast/multicol/span/before-child-anonymous-column-block-expected.txt
deleted file mode 100644
index 9a9034bd252728b19403b4f68ca95bbb4bff9c19..0000000000000000000000000000000000000000
--- a/LayoutTests/virtual/slimmingpaint/fast/multicol/span/before-child-anonymous-column-block-expected.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-layer at (0,0) size 800x600
-  LayoutView at (0,0) size 800x600
-layer at (0,0) size 800x52
-  LayoutBlockFlow {HTML} at (0,0) size 800x52
-    LayoutBlockFlow {BODY} at (16,16) size 768x20
-layer at (16,16) size 768x20
-  LayoutBlockFlow {DIV} at (0,0) size 768x20
-    LayoutMultiColumnSpannerPlaceholder (anonymous) at (0,0) size 0x0
-    LayoutMultiColumnSet (anonymous) at (0,0) size 768x20
-layer at (16,16) size 374x40
-  LayoutMultiColumnFlowThread (anonymous) at (0,0) size 374x40
-    LayoutBlockFlow {DIV} at (0,0) size 768x0
-    LayoutBlockFlow {DIV} at (0,0) size 374x20
-      LayoutText {#text} at (0,0) size 20x20
-        text run at (0,0) width 20: "3"
-    LayoutTable (anonymous) at (0,20) size 20x20
-      LayoutTableSection {DIV} at (0,0) size 20x20
-        LayoutTableRow (anonymous) at (0,0) size 20x20
-          LayoutTableCell (anonymous) at (0,0) size 20x20 [r=0 c=0 rs=1 cs=1]
-            LayoutText {#text} at (0,0) size 20x20
-              text run at (0,0) width 20: "4"