CI: make the Autodesk connector workflow a test gate, ship it on macOS

Three related cleanups to how the bonsaiviewer-autodesk connector is built
and shipped.

build-bonsaiviewer-autodesk.yml no longer builds a bundle. Its four-runner
matrix produced autodesk-<os>-<arch>.zip artifacts that nothing consumed —
shipping happens in the platform pipelines, which each invoke
packaging/build.py themselves. What is left is the crate's only lint and
test coverage, so the workflow is renamed to match what it does and a
header comment records where the shipped binary actually comes from.

build_osx.yml now builds and bundles the connector, which it never did:
macOS users have been getting a Bonsai Viewer with no Autodesk connector at
all. ConnectorDiscovery resolves applicationDirPath()/connectors, which
inside a bundle is Contents/MacOS, so that is where the folder lands.

The tkinter probes in the Windows and Linux workflows are dropped. They
guarded the old PyInstaller connector's Tk GUI (de7520418) and have been
dead since the Rust rewrite (9d9f4054f); python3.11-tkinter goes with them.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.github/workflows/build_rocky.yml

@@ -28,13 +28,12 @@ jobs:
                          sqlite-devel bzip2-devel zlib-devel openssl-devel xz-devel      \
                          readline-devel ncurses-devel libffi-devel libuuid-devel git-lfs \
                          findutils xz byacc patchelf libxkbcommon-devel                 \
-                         python3.11 python3.11-pip python3.11-tkinter \
+                         python3.11 python3.11-pip \
                          dbus-devel \
                          libXext-devel libXinerama-devel libXcursor-devel libXrender-devel \
                          libXfixes-devel libXft-devel pango-devel cairo-devel libstdc++-static
           python3 -m pip install aqtinstall
           git config --global --add safe.directory '*'
-          python3.11 -c "import tkinter; print('Tk', tkinter.TkVersion)"
 
       - name: Install Rust
         # The bonsaiviewer-autodesk connector is a Rust crate; the "Package