fix(script): pass current stable Clippy match lint

[ratovarius]

Description

Current stable Clippy rejects the nested Apps Script JSON filename match under the required -D warnings gate. Use a guarded match arm so appsscript.json remains the only accepted JSON source file, with the same behavior for all other extensions.

Fixes ratovarius#8.

Scope and integration

This is build-maintenance work, not a new Workspace feature. The same two-file Clippy patch is currently copied into each of #931–#937 so those branches pass the current stable-toolchain lint gate against the present upstream base. Merge this small common change first where practical; the remaining PRs can then be refreshed to omit the duplicate patch. The seven feature/fix PRs can otherwise be evaluated individually.

Local independent agent review found no outstanding findings. This does not represent upstream maintainer approval.

Validation

cargo fmt --all -- --check, cargo test --workspace --locked --offline (783 tests), and cargo clippy --workspace --locked --offline -- -D warnings passed on Rust 1.98.1. Independent review confirmed behavior equivalence.

Limits

No new CLI behavior; dry-run output is not applicable.

Checklist

• Follows AGENTS.md; no generated Google client crates.
• Formatting check passed.
• Required strict Clippy check passed.
• Existing regression tests verify unchanged file-selection behavior.
• Includes a changeset.

[changeset-bot]

🦋 Changeset detected

Latest commit: 48f1b8b

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@googleworkspace/cli	Patch

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[ratovarius]

Closing this proposal by author request to focus the initial upstream contribution on #937 (preserve saved credentials after authentication failures).

This work remains implemented and maintained in the public fork, https://github.com/ratovarius/cli, with tracking in ratovarius#8 and integration in ratovarius#10. Further development of this item will continue in the fork. This closure does not indicate rejection by upstream maintainers.

The small Clippy cleanup is already included as a separately reviewable commit in #937, so that pilot does not depend on this PR being merged.