Fix bftree_garnet.dll NuGet packaging

[tiagonapoli]

Problem

Microsoft.Garnet fails to consume on Windows with:

warning MSB3246: Resolved file has a bad image, no metadata, or is otherwise inaccessible.
Could not load file or assembly 'bftree_garnet.dll' or one of its dependencies.
The module was expected to contain an assembly manifest.

The native Rust library bftree_garnet.dll leaked into the package's lib/<tfm>/ folder,
where NuGet treats every DLL as a managed assembly. Because the native has no assembly
manifest, restore/build of any consumer emits MSB3246.

Root cause

PR #1933 added a fallback to BfTreeInterop.csproj that copies the committed
runtimes/<rid>/native/ binary to the build output root whenever a fresh cargo build
is absent (i.e. no Rust — the packaging build). From the output root the native propagated
through ProjectReference into Garnet.host's output root and was swept into lib/<tfm>
by Garnet.host.csproj's lib\*.dll wildcard.

#1933 added that fallback because, at the time, BfTreeInterop.test referenced only
BfTreeInterop and could not otherwise find the native without Rust. That is no longer
true (see below), so the fallback is pure liability now.

Fix

Structured as a clean, auditable revert-and-reapply:

1. Revert Fix RI.DEL failures from stale BfTree native binaries #1933 in full — removes the output-root fallback (the leak).
2. Re-apply the non-leak parts of Fix RI.DEL failures from stale BfTree native binaries #1933 — refresh the committed win-x64/linux-x64
   native binaries to match the current Rust FFI (bftree_delete returns an int status;
   fixes RangeIndex RI.DEL: invalid arguments), and drop the CI step that built the
   cdylib with cargo. The output-root fallback is deliberately NOT reintroduced.

Net change vs main: the 13-line output-root fallback removed from BfTreeInterop.csproj.
(The revert/re-apply of the CI step and binaries nets to zero.)

Why no resolver / no output-root copy is needed

bftree_garnet is a ProjectReference native staged only under runtimes/<rid>/native/.
A native library is loadable when its directory is on the NATIVE_DLL_SEARCH_DIRECTORIES
list, which the host builds from native runtimeTargets entries in the app's deps.json.
ProjectReference natives get no such entry — but NuGet-packaged natives (diskann, lua54)
do, and they register runtimes/win-x64/native/ and runtimes/linux-x64/native/. Since
bftree_garnet is staged in that same directory, it loads for free ("free-rides").

Since #1939, BfTreeInterop.test references Garnet.test (→ GarnetServer → diskann/lua54),
so its deps.json registers runtimes/<rid>/native/ and it free-rides exactly like every
other test host (e.g. Garnet.test.rangeindex). No output-root copy and no custom
DllImportResolver are required.

Verification

Windows (the actual bug), Release pack with no Rust:

package	native in lib/	native in runtimes/
main	lib/net8.0/bftree_garnet.dll, lib/net10.0/bftree_garnet.dll (leak)	present
this PR	none (fixed)	runtimes/{win-x64,linux-x64}/native/

Clean-room Linux Docker container (dotnet/sdk:10.0, no Rust toolchain, cloned fresh
from a git bundle — no host files copied):

• Full Garnet.slnx build (Release): 0 warnings, 0 errors, no MSB3246.
• BfTreeInterop.test: 46/46 pass with no output-root copy and no resolver — proving
  the diskann free-ride is sufficient.
• Garnet.test.rangeindex: 63/63 pass.

Also verified on Windows: full solution build plus BfTreeInterop.test 46/46 and
Garnet.test.rangeindex 63/63 without Rust.

[Copilot]

Pull request overview

This PR fixes NuGet packaging for the new Bf-Tree range index native binary by ensuring bftree_garnet.dll is not placed under lib/<tfm>/ (where NuGet/MSBuild treats it as a managed reference), and bumps the package version to ship the corrected layout.

Changes:

• Bump VersionPrefix from 2.0.1-beta.9 to 2.0.1-beta.10.
• Update Garnet.host.csproj pack globs to exclude the native bftree_garnet.dll from lib/net8.0 and lib/net10.0, while continuing to pack native assets via runtimes/**.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
Version.props	Bumps version to 2.0.1-beta.10 to publish the packaging fix.
libs/host/Garnet.host.csproj	Excludes bftree_garnet.dll from lib/<tfm> pack items so consumers don’t attempt to load it as a managed assembly; leaves runtime-native packing intact.