message: build: improve detection of eBPF support
  Just checking for the `sys/sdt.h` header isn't enough, as systems like
  macOS have the header, but it doesn't actually have the dtrace probes,
  which leads to compile failures.
diff: @@ -1369,13 +1369,15 @@ if test x$enable_wallet != xno; then
  fi
  if test x$use_ebpf != xno; then
  - AC_CHECK_HEADER([sys/sdt.h], [have_sdt=yes], [have_sdt=no])
  -else
  - have_sdt=no
  -fi
  -
  -if test x$have_sdt = xyes; then
  - AC_DEFINE([ENABLE_TRACING], [1], [Define to 1 to enable eBPF user static defined tracepoints])
  + AC_MSG_CHECKING([whether eBPF tracepoints are supported])
  + AC_COMPILE_IFELSE([
  + AC_LANG_PROGRAM(
  + [#include <sys/sdt.h>],
  + [DTRACE_PROBE("context", "event");]
  + )],
  + [AC_MSG_RESULT(yes); have_sdt=yes; AC_DEFINE([ENABLE_TRACING], [1], [Define to 1 to enable eBPF user static defined tracepoints])],
  + [AC_MSG_RESULT(no); have_sdt=no;]
  + )
  fi
  dnl Check for libminiupnpc (optional)
  