Cppcheck 2.12 download the new for apple

config-win32: set `HAVE_SNPRINTF` for mingw-w64.cmake: speed up threads setup for Windows.cmake: replace `check_library_exists_concat()`.cmake: pre-fill rest of detection values for Windows.

cmake: option to disable install & drop `curlu` target when unused.cmake: fix OpenSSL quic detection in quiche builds.cmake: fix multiple include of CURL package.

cmake: fix `HAVE_H_ERRNO_ASSIGNABLE` detection.cmake: add test for `DISABLE` options, add `CURL_DISABLE_HEADERS_API`.cmake: add `CURL_DISABLE_BINDLOCAL` option.CI: ignore test 286 on Appveyor gcc 9 build.CI: add autotools, out-of-tree, debug build to distro check job.

cfilter: provide call to tell connection to forget a socket.

build: fix libssh2 + `CURL_DISABLE_DIGEST_AUTH` + `CURL_DISABLE_AWS`.

build: fix compiler warning with auths disabled.

build: fix builds that disable protocols but not digest auth.

build: fix 'threadsafe' feature detection for older gcc.

build: delete support bits for obsolete Windows compilers.

build: delete `HAVE_STDINT_H` and `HAVE_INTTYPES_H`.

build: always revert `#pragma GCC diagnostic` after use.

build: add more picky warnings and fix them.

build: add `src/.checksrc` to source tarball.

autotools: update references to deleted `crypt-auth` option.

autotools: stop setting `-std=gnu89` with `-enable-warnings`.

autotools: fix/improve gcc and Apple clang version detection.

autotools: delete LCC compiler support bits.

autotools: avoid passing `LDFLAGS` twice to libcurl.

autotools: accept linker flags via `CURL_LDFLAGS_`.

asyn-thread: use pipe instead of socketpair for IPC when available.

appveyor: make VS2008-built curl tool runnable.

HTTP3: ngtcp2 builds are no longer experimental.

Cppcheck 2.12 download the new for apple