fix(tsconfig): stop reporting tsconfig files as file dependencies

[stormslowly]

Why

load_tsconfig_paths pushed the whole accumulated tsconfig.file_dependencies set — the root tsconfig, everything it extends, and every transitive project reference — into ResolveContext on every resolution that hit a tsconfig path alias.

In a monorepo with project references that set is large, and the consumer keeps it per module, so the cost scales as module count × tsconfig count. That is the memory burst this PR addresses.
Here is an issue from user web-infra-dev/rspack#15021

Resolving @/index.ts in the project_references fixture:

Before — 6 tsconfig paths on top of the real dependencies:

app/tsconfig.json
tsconfig.base.json
project_a/conf.json
project_b/tsconfig.json
project_c/tsconfig.json
paths_template_variable/tsconfig2.json
project_b/src/aliased/index.ts
fixtures/tsconfig/package.json

After:

project_b/src/aliased/index.ts
fixtures/tsconfig/package.json

Trade-off

This is a temporary workaround, not a fix. Editing a tsconfig.json, a config it extends, or a referenced tsconfig no longer invalidates anything in watch mode — a dev server restart is required.

It is written to be undone in one commit:

• the loop in load_tsconfig_paths is commented out rather than deleted, with a TODO pointing at the test
• tsconfig_file_as_file_dependencies is marked #[ignore] rather than removed, so the expected dependency set stays recorded
• TsConfig::file_dependencies and its accumulation in extend_tsconfig / load_references are untouched

Restoring means uncommenting the loop and dropping the #[ignore].

[Copilot]

Pull request overview

Reduces per-module memory growth during tsconfig path-alias resolution by no longer copying the accumulated TsConfig::file_dependencies set into ResolveContext (which downstream consumers keep per module).

Changes:

• Stop adding tsconfig.file_dependencies into ResolveContext during load_tsconfig_paths.
• Ignore the existing test that asserted tsconfig configs/references are reported as file dependencies (preserving it as a reference for later restoration).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/lib.rs	Disables propagation of tsconfig.file_dependencies into ResolveContext to prevent module count × tsconfig count scaling in downstream memory usage.
src/tests/tsconfig_project_references.rs	Marks the prior “tsconfig configs are file deps” assertion test as ignored while the workaround is in place.

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[codspeed-hq]

Merging this PR will not alter performance

✅ 12 untouched benchmarks

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_{Comparing fix/skip-tsconfig-file-dependencies (8baf259) with main (ab14d9d)}