Merge bitcoin/bitcoin#26086: build: remove BOOST_CPPFLAGS usage from bitcoin-tx

f839697d9b build: remove BOOST_CPPFLAGS usage from bitcoin-tx (fanquake)

Pull request description:

  The only reason `BOOST_CPPFLAGS` was needed here, is because of the `policy/rbf.h` include, which ultimately includes boost multi_index via `txmempool.h`. However this include is unused.

ACKs for top commit:
  theuni:
    Nice. ACK f839697d9b.
  hebasto:
    ACK f839697d9b, tested on Linux x86_64 using theuni's [patch](https://github.com/theuni/bitcoin/commit/e131d8f1e33baa9a9499d2e1a4a99b171566c5a5) with depends.

Tree-SHA512: ec93f4045d927789d70e2a96a6869c0df63891483bb61361327bfefafaabc2925f63382aa3d9302963df2306bc035edad4cabd5eeb315db6603266e677be7cd3

src/Makefile.am

@@ -772,7 +772,7 @@ bitcoin_cli_LDADD += $(EVENT_LIBS)
 
 # bitcoin-tx binary #
 bitcoin_tx_SOURCES = bitcoin-tx.cpp
-bitcoin_tx_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(BOOST_CPPFLAGS)
+bitcoin_tx_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 bitcoin_tx_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 bitcoin_tx_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) $(PTHREAD_FLAGS)
 

src/bitcoin-tx.cpp

@@ -15,7 +15,6 @@
 #include <key_io.h>
 #include <fs.h>
 #include <policy/policy.h>
-#include <policy/rbf.h>
 #include <primitives/transaction.h>
 #include <script/script.h>
 #include <script/sign.h>