build: fix stdint/inttypes detection with non-autotools

Fix `stdint.h` and `inttypes.h` detection with non-autotools builds on
Windows. (autotools already auto-detected them accurately.)

`lib/config-win32.h` builds (e.g. `Makefile.mk`):
- set `HAVE_STDINT_H` where supported.
- set `HAVE_INTTYPES_H` for MinGW.

CMake:
- auto-detect them on Windows. (They were both force-disabled.)
- delete unused `CURL_PULL_STDINT_H`.
- delete unused `CURL_PULL_INTTYPES_H`.
- stop detecting `HAVE_STDINT_H` twice.
  Present since the initial CMake commit: 4c5307b456

curl doesn't use these C99 headers, we need them now to workaround
broken wolfSSL builds. Ref: #10739

Once that clears up, we can delete these detections and macros (unless
we want to keep them for future us.)

Reviewed-by: Daniel Stenberg
Closes #10745

CMakeLists.txt

@@ -989,7 +989,6 @@ check_include_file_concat("unistd.h"         HAVE_UNISTD_H)
 check_include_file_concat("utime.h"          HAVE_UTIME_H)
 
 check_include_file_concat("stddef.h"         HAVE_STDDEF_H)
-check_include_file_concat("stdint.h"        HAVE_STDINT_H)
 check_include_file_concat("sys/utsname.h"   HAVE_SYS_UTSNAME_H)
 
 check_type_size(size_t  SIZEOF_SIZE_T)
@@ -1263,8 +1262,6 @@ else()
   set(CURL_PULL_SYS_SOCKET_H ${HAVE_SYS_SOCKET_H})
   set(CURL_PULL_SYS_POLL_H ${HAVE_SYS_POLL_H})
 endif()
-set(CURL_PULL_STDINT_H ${HAVE_STDINT_H})
-set(CURL_PULL_INTTYPES_H ${HAVE_INTTYPES_H})
 
 include(CMake/OtherTests.cmake)