fix(codegen): remove double indentation for enum inside namespace

[Dunqing]

Summary

• TSEnumDeclaration::gen() called p.print_indent(), but the Statement handler already calls print_indent() before dispatching — causing enums inside namespaces to get double indentation (e.g. 4 spaces instead of 2).
• No other declaration type (Class, TSModuleDeclaration, TSInterfaceDeclaration, TSTypeAliasDeclaration) has this issue.

Before:

declare namespace ns {
  class Foo {}
    enum Bar {}
  type Baz = undefined;
}

After:

declare namespace ns {
  class Foo {}
  enum Bar {}
  type Baz = undefined;
}

Test plan

• Added test_same case for declare namespace with class, enum, and type alias
• Verified test fails without the fix, passes with it
• All 92 oxc_codegen tests pass

🤖 Generated with Claude Code

[codspeed-hq]

Merging this PR will not alter performance

✅ 52 untouched benchmarks
⏩ 3 skipped benchmarks¹

---

_{Comparing fix/codegen-enum-indent (a813d79) with main (805ee60)}

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[camc314]

Merge activity

• Feb 27, 12:17 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Feb 27, 12:23 PM UTC: camc314 added this pull request to the Graphite merge queue.
• Feb 27, 12:30 PM UTC: Merged by the Graphite merge queue.