Merge #17382: rpc: Remove unused boost::this_thread::interruption_point

fa5facd3e7 rpc: Remove unused boost::this_thread::interruption_point (MarcoFalke)

Pull request description:

  There are predefined interruption points for `boost::thread`: https://www.boost.org/doc/libs/1_71_0/doc/html/thread/thread_management.html#interruption_points

  However, the rpc threads are `std::thread`, which does not have an `std::thread::interrupt` member function to request interruption: https://dev.visucore.com/bitcoin/doxygen/httpserver_8cpp.html#ae1a63374e18b9abd348eb74e4243ea34

  Thus, the interruption points can be removed.

ACKs for top commit:
  laanwj:
    ACK fa5facd3e7, this does nothing.
  practicalswift:
    ACK fa5facd3e7
  jamesob:
    ACK fa5facd3e7

Tree-SHA512: 4e29a44df1f2702cbd1ffdffa559440a8bb800baab64b4116e2c3d27cd64d8d1e8aafe1dc21b1a4e3988470d03be19cae294bd5669f7abf6d487685dc8fd8d7e

src/rpc/blockchain.cpp

@@ -39,8 +39,6 @@
 
 #include <univalue.h>
 
-#include <boost/thread/thread.hpp> // boost::thread::interrupt
-
 #include <condition_variable>
 #include <memory>
 #include <mutex>
@@ -1976,7 +1974,6 @@ bool FindScriptPubKey(std::atomic<int>& scan_progress, const std::atomic<bool>&
         Coin coin;
         if (!cursor->GetKey(key) || !cursor->GetValue(coin)) return false;
         if (++count % 8192 == 0) {
-            boost::this_thread::interruption_point();
             if (should_abort) {
                 // allow to abort the scan via the abort reference
                 return false;