test: Trim lockfile-aware caching integration matrix (#12995)
## Why
`lockfile_aware_caching_test` repeated the same expensive binary
cache/filter scenario across five package managers. The
package-manager-specific contract is lockfile change scoping, which can
be tested directly without spawning `turbo` and package manager scripts
for each variant.
## What
- Added lower-level `PackageGraph::changed_packages_from_lockfile`
coverage for npm, Yarn, pnpm, Berry, and Bun using the existing
lockfile-aware fixtures and patches.
- Kept the npm binary integration test as the end-to-end smoke for cache
hit/miss and `--filter=[HEAD^1]` behavior.
- Removed the duplicate Yarn, pnpm, Berry, and Bun binary variants.
## How
Verified locally with:
- `cargo test -p turborepo-repository
lockfile_changes_are_scoped_by_package_manager`
- `cargo nextest run -p turbo --test lockfile_aware_caching_test`
- `git diff --check`
This keeps package-manager-specific lockfile scoping coverage while
reducing the subprocess-heavy integration matrix.
