[dev-db/mongodb] bump 6 series, tree candidate

dev-db/mongodb/files/mongodb-6.0.20-gcc-11.patch

@@ -0,0 +1,12 @@
+https://bugs.gentoo.org/768339
+
+--- a/src/mongo/db/exec/plan_stats.h
++++ b/src/mongo/db/exec/plan_stats.h
+@@ -33,6 +33,7 @@
+ #include <cstdlib>
+ #include <string>
+ #include <vector>
++#include <optional>
+ 
+ #include "mongo/db/exec/plan_stats_visitor.h"
+ #include "mongo/db/index/multikey_paths.h"