Remove unnecessary external dependencies

[UebelAndre]

Addresses some failures identified in #3077

[UebelAndre]

E.g. https://buildkite.com/bazel/rules-rust-rustlang/builds/13191#0193b2c6-8dc8-4b16-899b-d6e0d2e8070e

(22:53:23) ERROR: Skipping '//...': error loading package under directory '': error loading package '': Unable to find package for @@[unknown repo 'aspect_bazel_lib' requested from @@]//lib:transitions.bzl: The repository '@@[unknown repo 'aspect_bazel_lib' requested from @@]' could not be resolved: No repository visible as '@aspect_bazel_lib' from main repository. Was the repository introduced in WORKSPACE? The WORKSPACE file is disabled by default in Bazel 8 (late 2024) and will be removed in Bazel 9 (late 2025), please migrate to Bzlmod. See https://bazel.build/external/migration.
(22:53:23) ERROR: error loading package under directory '': error loading package '': Unable to find package for @@[unknown repo 'aspect_bazel_lib' requested from @@]//lib:transitions.bzl: The repository '@@[unknown repo 'aspect_bazel_lib' requested from @@]' could not be resolved: No repository visible as '@aspect_bazel_lib' from main repository. Was the repository introduced in WORKSPACE? The WORKSPACE file is disabled by default in Bazel 8 (late 2024) and will be removed in Bazel 9 (late 2025), please migrate to Bzlmod. See https://bazel.build/external/migration.

This directory probably should have bzlmod but I think reducing dependencies only used for small things is a good thing to do.