fix: don't attach @module JSDoc to the first symbol

[fibibot]

Summary

Reported as denoland/deno#30783. `js_doc_for_range_include_ignore` walks leading comments back from a symbol's range to find its JSDoc block. When a file's `@module` documentation comment was the only leading block before an undocumented exported symbol, that comment was returned as the symbol's JSDoc — so the same paragraph appeared twice in `deno doc` output and on an unrelated symbol:

```js
/**

• The module docs.
• @module
  */

export function foo() {}

/** This is the bar function. */
export function bar() {}
```

```
$ deno doc bug.js
The module docs.
@module

Defined in file:///bug.js:9:1

function bar(): void
This is the bar function.

Defined in file:///bug.js:6:1

function foo(): void
The module docs. <-- duplicated module-level doc
@module
```

Skip JSDoc blocks tagged `@module` when resolving per-symbol docs. They're file-level by intent and have already been collected by `module_js_doc_for_source`.

Test plan

• New `tests/specs/module_docs_undocumented_first_symbol.txt` spec captures the regression — the regenerated output (via `UPDATE=1`) shows `foo` with no `jsDoc` field and `module_doc` containing the `@module` block.
• Existing `module_docs`, `module_docs_ignore`, `module_docs_ignore_no_module_tag` specs still pass.
• `cargo fmt --check`, `cargo clippy --tests -- -D warnings`.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ crowlKats
❌ fibibot
_{You have signed the CLA already but the status is still pending? Let us recheck it.}