Fix boost 1.86.0 recipe for x86 arch (#25887)

* Fix boost 1.86.0 build for x86 arch

* Fix minor syntax error

recipes/boost/all/conanfile.py

@@ -621,7 +621,7 @@ def _stacktrace_from_exception_available(self):
             return not self.options.header_only and not self.options.without_stacktrace and self.settings.os != "Windows"
         elif Version(self.version) >= "1.86.0":
             # https://github.com/boostorg/stacktrace/blob/boost-1.86.0/build/Jamfile.v2#L148
-            return not self.options.header_only and not self.options.without_stacktrace and self.settings.arch == "x86_64"
+            return not self.options.header_only and not self.options.without_stacktrace and self._b2_architecture == "x86"
 
     def configure(self):
         if self.options.header_only: