chore(release): Add shim tool (#562)

### Changes are visible to end-users: no

### Test plan

```shellsession
❯ DEST=$(realpath artifacts/) bazel run //tools/release:copy_release_artifacts
INFO: Analyzed target //tools/release:copy_release_artifacts (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
Target //tools/release:copy_release_artifacts up-to-date:
  bazel-bin/tools/release/copy_release_artifacts
INFO: Elapsed time: 0.782s, Critical Path: 0.00s
INFO: 1 process: 1 internal.
INFO: Build completed successfully, 1 total action
INFO: Running command line: bazel-bin/tools/release/copy_release_artifacts aspect_rules_py/py/tools/unpack_bin/unpack-aarch64-apple-darwin aspect_rules_py/py/tools/unpack_bin/unpack-aarch64-apple-darwin.sha256 aspect_rules_py/py/tools/unpack_bin/unpack-x86_64-apple-darwin aspect_rules_py/py/tools/unpack_bin/unpack-x86_64-apple-darwin.sha256 aspect_rules_py/py/tools/venv_bin/venv-aarch64-apple-darwin aspect_rules_py/py/tools/venv_bin/venv-aarch64-apple-darwin.sha256 aspect_rules_py/py/tools/venv_bin/venv-x86_64-apple-darwin aspect_rules_py/py/tools/venv_bin/venv-x86_64-apple-darwin.sha256 aspect_rules_py/py/tools/venv_shim/shim-aarch64-apple-darwin aspect_rules_py/py/tools/venv_shim/shim-aarch64-apple-darwin.sha256 aspect_rules_py/py/tools/venv_shim/shim-x86_64-apple-darwin aspect_rules_py/py/tools/venv_shim/shim-x86_64-apple-darwin.sha256
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/unpack_bin/unpack-aarch64-apple-darwin -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/unpack-aarch64-apple-darwin
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/unpack_bin/unpack-aarch64-apple-darwin.sha256 -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/unpack-aarch64-apple-darwin.sha256
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/unpack_bin/unpack-x86_64-apple-darwin -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/unpack-x86_64-apple-darwin
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/unpack_bin/unpack-x86_64-apple-darwin.sha256 -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/unpack-x86_64-apple-darwin.sha256
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/venv_bin/venv-aarch64-apple-darwin -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/venv-aarch64-apple-darwin
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/venv_bin/venv-aarch64-apple-darwin.sha256 -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/venv-aarch64-apple-darwin.sha256
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/venv_bin/venv-x86_64-apple-darwin -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/venv-x86_64-apple-darwin
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/venv_bin/venv-x86_64-apple-darwin.sha256 -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/venv-x86_64-apple-darwin.sha256
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/venv_shim/shim-aarch64-apple-darwin -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/shim-aarch64-apple-darwin
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/venv_shim/shim-aarch64-apple-darwin.sha256 -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/shim-aarch64-apple-darwin.sha256
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/venv_shim/shim-x86_64-apple-darwin -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/shim-x86_64-apple-darwin
/private/var/tmp/_bazel_arrdem/93bfea6cdc1153cc29a75400cd38823a/execroot/aspect_rules_py/bazel-out/darwin_arm64-fastbuild/bin/py/tools/venv_shim/shim-x86_64-apple-darwin.sha256 -> /Users/arrdem/Documents/work/aspect/rules_py/artifacts/shim-x86_64-apple-darwin.sha256
```

Author: arrdem

tools/release/BUILD.bazel

@@ -21,11 +21,13 @@
 LINUX_ARTIFACTS = [
     "//py/tools/unpack_bin:unpack_linux",
     "//py/tools/venv_bin:venv_linux",
+    "//py/tools/venv_shim:shim_linux",
 ]
 
 MACOS_ARTIFACTS = [
     "//py/tools/unpack_bin:unpack_macos",
     "//py/tools/venv_bin:venv_macos",
+    "//py/tools/venv_shim:shim_macos",
 ]
 
 sh_binary(