wpt: Unskip the `css-tables suite (#31131)

This will be useful for tracking improvements to table support.

tests/wpt/meta/css/css-tables/column-track-merging.html.ini

@@ -0,0 +1,36 @@
+[column-track-merging.html]
+  [main table 1]
+    expected: FAIL
+
+  [main table 2]
+    expected: FAIL
+
+  [main table 3]
+    expected: FAIL
+
+  [main table 4]
+    expected: FAIL
+
+  [main table 5]
+    expected: FAIL
+
+  [main table 6]
+    expected: FAIL
+
+  [main table 7]
+    expected: FAIL
+
+  [main table 8]
+    expected: FAIL
+
+  [main table 10]
+    expected: FAIL
+
+  [main table 11]
+    expected: FAIL
+
+  [main table 12]
+    expected: FAIL
+
+  [main table 13]
+    expected: FAIL