enhance: support building core on macOS (Apple Silicon) with clang 19 (#50616)

issue: #50615

## What this PR does
Makes the C++ core build cleanly on **macOS (Apple Silicon) with
Homebrew LLVM/clang 19**.

> [!IMPORTANT]
> **Scope / impact is NOT macOS-only.** Although this PR is framed as
macOS/clang-19 enablement, two of the changes are **top-level
`requires(...)` in `internal/core/conanfile.py`, so they apply to every
platform, including Linux production builds:**
> - **`azure-sdk-for-cpp` `1.11.3@milvus/dev` → `1.16.0@milvus/dev`** (5
minor versions, `force=True`). This is the SDK Arrow uses for the
**Azure Blob remote-storage path**, so this is effectively a major Azure
SDK bump on the **production Azure object-storage path for Linux
deployments** too.
> - **`arrow` recipe `17.0.0@milvus/dev-2.6#c743ea7a…` →
`17.0.0@milvus/dev#f411aa73…`** — same Arrow version, but **rebuilt
against azure 1.16.0** with a patched `FindAzure.cmake`. The Arrow
**`package_id` (recipe revision) DID change**; it is not the same binary
as before.
> - **`libbson/1.30.6@milvus/dev`** added (also global, but new — no
pre-existing behavior to regress).
>
> **Testing blind spot:** CI green proves compile/link/UT/e2e pass, but
the UT and integration suites **do not exercise real Azure Blob
read/write**, so the Azure object-storage path is **not covered** by
this PR's CI. A real Azure Blob remote-storage regression is recommended
before merge (see Verification).

### Why the dependency bumps are required for clang 19
- **azure 1.16.0**: azure 1.11.3 bundles an older `nlohmann/json` that
uses `std::char_traits<unsigned char>`, which was **removed in libc++
19** → 1.11.3 fails to compile on clang 19. 1.16.0 fixes this.
- **arrow rebuilt against azure 1.16.0**: when Arrow is built from
source on clang 19 it must link the same azure 1.16.0; the recipe also
patches `FindAzure.cmake` to the monolithic `Azure` config so
`find_package(Azure)` resolves. Hence a new Arrow recipe revision.

### Toolchain / build enablement
- **`scripts/setenv.sh`**: probe LLVM 19/20/21 first (libc++ 17/18
`chrono operator<<` clashes with Arrow's vendored `date`; libc++ 19
fixes it).
- **`scripts/3rdparty_build.sh`**: arm64 `-march=armv8-a+crypto+crc` so
folly's F14 (SimdAndCrc on Apple Silicon) matches core/knowhere — fixes
`F14LinkCheck` undefined-symbol link errors.
- **`InvertedIndexTantivy.cpp`**: drop spurious `->template` on
non-template members (clang 19
`-Wmissing-template-arg-list-after-template-kw`).

### Drop bsoncxx / libmongoc → libbson only
The BSON layer used the **bsoncxx** C++ driver, whose CMake
unconditionally builds mongo-cxx-driver → **libmongoc** → bundled
**utf8proc**, which fails to configure under newer CMake/clang on macOS.
Milvus only needs BSON (de)serialization.

- New Conan package **`libbson/1.30.6@milvus/dev`** (libbson-only,
`ENABLE_MONGOC=OFF`; recipe published to milvus conanfiles &
production).
- New **`src/common/bson_shim.h`** — a thin `milvus::bson` C++ layer
over libbson's C API.
- Migrated `bson_view.h`, `bson_builder.{h,cpp}`, json_stats consumers
and unit tests off bsoncxx.
- CMake: `find_package(bson-1.0)` + link `mongo::bson_shared`; removed
FetchContent `thirdparty/bsoncxx`.

All three global Conan requires (arrow / libbson / azure) pin an
explicit recipe `#revision` for reproducibility.

## Verification
- Full clean rebuild on macOS arm64 / clang 19: `bin/milvus` builds;
`libmilvus_core` links **only `libbson-1.0.dylib`** (no
libmongoc/mongocxx/utf8proc).
- libbson / arrow / azure resolve from production Conan at the pinned
revisions.
- All 21 BSON unit tests (BsonView / BsonBuilder / DomNode) pass.
- Full ci-v2 suite green on Linux (build / build-ut-cov / ut-cpp / ut-go
/ integration / e2e / go-sdk).
- **TODO before merge:** real Azure Blob remote-storage read/write
regression to cover the azure-1.16.0 / arrow-rebuild blast radius (not
exercised by UT/integration).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Signed-off-by: xiaofanluan <xf@hjjaq.com>
Co-authored-by: xiaofanluan <xf@hjjaq.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/3rdparty_build.sh

@@ -141,7 +141,10 @@ if [[ "$(uname -s)" == "Darwin" ]]; then
     arm_crypto_flags=""
     if [[ "$(uname -m)" == "arm64" ]]; then
         # Homebrew LLVM needs ARM crypto enabled for libsodium armcrypto sources on macOS arm64.
-        arm_crypto_flags=" -march=armv8-a+crypto"
+        # +crc: Apple Silicon enables __ARM_FEATURE_CRC32 by default, so milvus core/knowhere
+        # compile folly's F14 hash table in SimdAndCrc mode. 3rdparty deps (folly) must match,
+        # else folly::f14::F14LinkCheck<mode> is undefined at link time.
+        arm_crypto_flags=" -march=armv8-a+crypto+crc"
     fi
     export CFLAGS="${CFLAGS} -DTARGET_OS_OSX=1${arm_crypto_flags}"
     export CXXFLAGS="${CXXFLAGS} -DTARGET_OS_OSX=1${arm_crypto_flags}"

scripts/setenv.sh

@@ -60,8 +60,10 @@ case "${unameOut}" in
       export LD_LIBRARY_PATH="${LD_LIBRARY_PATH:+$LD_LIBRARY_PATH:}$MILVUS_LIB_DIRS"
       export RPATH=$MILVUS_LIB_DIRS;;
     Darwin*)
-      # detect llvm version by valid list (supports LLVM 14-18)
-      for llvm_version in 18 17 16 15 14 NOT_FOUND ; do
+      # detect llvm version by valid list (supports LLVM 14-21)
+      # Prefer 19+ on macOS: libc++ 17/18 has a chrono operator<< that conflicts
+      # with arrow's vendored date library; libc++ 19 resolves it.
+      for llvm_version in 21 20 19 18 17 16 15 14 NOT_FOUND ; do
         if brew ls --versions llvm@${llvm_version} > /dev/null 2>&1; then
           break
         fi