Drop Map.merge as taint step

Author: aibaars

java/ql/src/semmle/code/java/dataflow/internal/ContainerFlow.qll

@@ -112,7 +112,7 @@ private predicate taintPreservingQualifierToMethod(Method m) {
   // java.util.Map
   m
       .(MapMethod)
-      .hasName(["computeIfAbsent", "entrySet", "get", "getOrDefault", "merge", "put", "putIfAbsent",
+      .hasName(["computeIfAbsent", "entrySet", "get", "getOrDefault", "put", "putIfAbsent",
             "remove", "replace", "values"])
   or
   // java.util.Collection

java/ql/test/library-tests/dataflow/collections/flow.expected

@@ -61,7 +61,6 @@
 | ContainterTest.java:43:4:43:26 | map | ContainterTest.java:162:8:162:21 | entrySet(...) |
 | ContainterTest.java:43:4:43:26 | map | ContainterTest.java:163:8:163:21 | get(...) |
 | ContainterTest.java:43:4:43:26 | map | ContainterTest.java:164:8:164:41 | getOrDefault(...) |
-| ContainterTest.java:43:4:43:26 | map | ContainterTest.java:165:8:165:50 | merge(...) |
 | ContainterTest.java:43:4:43:26 | map | ContainterTest.java:166:8:166:30 | put(...) |
 | ContainterTest.java:43:4:43:26 | map | ContainterTest.java:167:8:167:38 | putIfAbsent(...) |
 | ContainterTest.java:43:4:43:26 | map | ContainterTest.java:168:8:168:27 | remove(...) |