fix: exclude vendored generic-btree from releases

[zxch3n]

Summary:

• Always exclude the vendored generic-btree workspace crate from Rust releases.
• Merge the fixed exclusion with automatically detected unchanged crates and deduplicate flags.

Rationale:

• generic-btree is a verbatim in-tree copy of crates.io 0.10.7. The release script would otherwise bump it to the Loro product version and rewrite published dependency ranges.

Validation:

• deno fmt --check scripts/cargo-release.ts
• deno check --node-modules-dir=auto scripts/cargo-release.ts
• isolated 1.13.7 release-script run produced the expected exclusions and kept generic-btree at 0.10.7 with dependencies at ^0.10.7.

[github-actions]

WASM Size Report

• Original size: 3053.29 KB
• Gzipped size: 1009.20 KB
• Brotli size: 707.44 KB