test(npm): cover Yarn 3.x PnP format and Bazel 8

Extend the Berry lockfile parser to metadata version 6 (Yarn 3.x): bare
sha512 checksums without a cache-key prefix and unquoted dependency
ranges, validated against artifacts generated by a real Yarn 3.8.7
install in the new e2e/pnp_zero_install_yarn3 fixture.

Yarn 3 support is import/verification only: pnp_verify_test passes
against the Yarn 3 cache, but the Yarn 3 .pnp.cjs runtime loads a second
instance of itself when the project is reachable through more than one
path spelling (as under Bazel's runfiles and output trees) and recurses
until the stack overflows, so runtime execution stays Yarn 4+ and the
limitation is documented in the fixture.

The Yarn 4 e2e (runtime + verification) also passes on Bazel 8.4.2 in
addition to 7.7.1.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013hsnpEj9uwyqyFo4W9swPQ

Author: claude

e2e/pnp_zero_install_yarn3/.gitignore

@@ -0,0 +1 @@
+.yarn/install-state.gz