Fix macOS ARM64 build for picodata

[MBHuman]

Fix macOS ARM64 build for picodata via tarantool-sys

This PR updates the tarantool-sys submodule to fix build issues of
picodata/picodata on macOS ARM64
(Apple Silicon).

Problem description

When building picodata on macOS ARM64:

• CMAKE_OSX_SYSROOT was unset, causing bundled dependencies (SASL, LDAP,
  autotools-based libs) to fail with missing headers or unresolved symbols.
• The xxhash sub-build used -Ofast, which produced compatibility issues on
  Apple Clang.
• Static linking flags were incorrectly applied under Clang due to too narrow
  compiler ID checks.
• The small submodule leaked its root directory into include paths, breaking
  builds.
• For ExternalProject_Add, the macOS SDK path was not propagated, leading to
  inconsistent sysroot usage in child projects.

As a result, picodata could not be built from master on Apple Silicon.

Fixes

• Detect and set CMAKE_OSX_SYSROOT automatically via xcrun --show-sdk-path.
• Pass -DCMAKE_OSX_SYSROOT explicitly to ExternalProject_Add on macOS.
• Replace -Ofast with -O3 for xxhash.
• Adjust Clang detection when adding -static-libstdc++.
• Clean up INCLUDE_DIRECTORIES for small targets.

Result

With this update in tarantool-sys, the picodata/picodata project builds
successfully on macOS ARM64.