tsgo: Fix TypeScript type errors in e2e test projects (#47426)

* tsgo: Fix TypeScript type errors in e2e test projects

* Update JSDoc comment

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/22625509118

Upstream-Ref: Automattic/jetpack@5d9c758

Author: manzoorwanijk

CHANGELOG.md

@@ -18,6 +18,7 @@ This is an alpha version! The changes listed here are not final.
 
 ### Fixed
 - Ensure proper flags are used with `json_encode()`.
+- Fix TS errors detected by tsgo.
 
 ## [3.0.3] - 2025-11-11
 ### Added