Merge bitcoin/bitcoin#24740: doc: remove incorrect mention of PR_GET_NAME

e8fc236 refactor: add missing std:: includes to threadnames.cpp (fanquake)
87f3c04 doc: remove incorrect mention of PR_GET_NAME (fanquake)

Pull request description:

  By removing the whole comment. These `#include // For` comments are near impossible
  to maintain, pollute diffs, and generally don't add a lot of value.

  While here, also add the missing `std::` includes.

ACKs for top commit:
  junderw:
    LGTM ACK e8fc236

Tree-SHA512: d29aff40c94f59c42f295a5738bc5ff2f4a2f2e6d270cc505f27d56d07d272597e2f8403d72fe45775661e1a1fc2af9fc52aeaeb41263bd3e9dfe255332383c8

Author: fanquake

src/util/threadnames.cpp

@@ -6,7 +6,9 @@
 #include <config/bitcoin-config.h>
 #endif
 
+#include <string>
 #include <thread>
+#include <utility>
 
 #if (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
 #include <pthread.h>
@@ -16,7 +18,7 @@
 #include <util/threadnames.h>
 
 #ifdef HAVE_SYS_PRCTL_H
-#include <sys/prctl.h> // For prctl, PR_SET_NAME, PR_GET_NAME
+#include <sys/prctl.h>
 #endif
 
 //! Set the thread's name at the process level. Does not affect the