Merge bitcoin#28145: valgrind: add suppression for bug 472219

50f7214 valgrind: add suppression for bug 472219 (fanquake)

Pull request description:

  Now that https://bugs.kde.org/show_bug.cgi?id=472219 has been fixed upstream in:

  https://sourceware.org/git/?p=valgrind.git;a=commit;h=6ce0979884a8f246c80a098333ceef1a7b7f694d

  Add a supression to ignore the bug until we are using a fixed version of Valgrind.

  Related to bitcoin#28072.

ACKs for top commit:
  MarcoFalke:
    lgtm ACK 50f7214

Tree-SHA512: 1030f3709195250350fd9c558420a9b1773fb54fdb323e0452a46eeb69ec6d60b5df50bde617c12d917e16dde07db64dee1b0101ddd4eda6161261fc7f6d4474

contrib/valgrind.supp

@@ -89,3 +89,9 @@
    ...
    fun:_ZN5BCLog6Logger12StartLoggingEv
 }
+{
+   Suppress https://bugs.kde.org/show_bug.cgi?id=472219 - fixed in Valgrind 3.22.
+   Memcheck:Param
+   ppoll(ufds.events)
+   obj:/lib/ld-musl-aarch64.so.1
+}