PHPC-1174: Remove traces of bson-stdint.h

The output path for this file was left incorrect in the previous PR for PHPC-1174, but the file isn't actually even used anymore per mongodb/mongo-c-driver@abc882d (CDRIVER-2473).

Author: jmikola

config.m4

@@ -245,7 +245,6 @@ if test "$PHP_MONGODB" != "no"; then
 
     dnl Avoid using AC_CONFIG_MACRO_DIR, which might conflict with PHP
     _include([scripts/autotools/m4/ac_compile_check_sizeof.m4])
-    _include([scripts/autotools/m4/ac_create_stdint_h.m4])
     _include([scripts/autotools/m4/as_var_copy.m4])
     _include([scripts/autotools/m4/ax_check_compile_flag.m4])
     _include([scripts/autotools/m4/ax_prototype.m4])

scripts/autotools/libbson/CheckHeaders.m4

@@ -4,8 +4,6 @@ if test "$ac_cv_header_stdbool_h" = "yes"; then
     AC_SUBST(BSON_HAVE_STDBOOL_H, 1)
 fi
 
-AC_CREATE_STDINT_H([$srcdir/src/libbson/src/bson/bson-stdint.h])
-
 AC_CHECK_HEADER([strings.h],
                 [AC_SUBST(BSON_HAVE_STRINGS_H, 1)],
                 [AC_SUBST(BSON_HAVE_STRINGS_H, 0)])