fix(es/plugin): use #[cfg] to avoid compilation error

[CPunisher]

Description:
#11267 introduced this mistake.

• SHARED_RUNTIME.block_on(fut) is enabled with#[cfg(feature = "plugin")]
• SHARED_RUNTIME is enabled with #[cfg(all(feature = "plugin", not(feature = "manual-tokio-runtime")))]
• If both features are enabled, the compiler goes failed.

The problem is that cfg! doesn't remove the code actually. #[cfg] is needed here

[changeset-bot]

🦋 Changeset detected

Latest commit: 15789f7

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[Copilot]

Pull Request Overview

This PR fixes a compilation error caused by incorrect use of cfg!() macro instead of #[cfg] attributes for conditional compilation. The issue occurs when both plugin and manual-tokio-runtime features are enabled together, causing the code to reference SHARED_RUNTIME which is only defined when manual-tokio-runtime is not enabled.

• Replaced runtime cfg!() macro check with compile-time #[cfg] attributes
• Reorganized imports and variable declarations to be scoped within the appropriate feature flag blocks
• Maintained error handling context for the non-manual runtime path

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[codspeed-hq]

CodSpeed Performance Report

Merging #11316 will not alter performance

_{Comparing CPunisher:11-20-fix/plugin-manual-tokio-runtime (15789f7) with main (387ee0f)¹}

Summary

✅ 138 untouched

Footnotes

1. No successful run was found on main (f98ca27) during the generation of this report, so 387ee0f was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[Copilot]

Pull Request Overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

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[github-actions]

Binary Sizes

File	Size
swc.linux-x64-gnu.node	31M (31947080 bytes)

Commit: af8b34c