chore: remove redundant target overrides from package tsconfigs

[cryptodev-2s]

Explanation

References

• Follow up to chore: opt into Jest types per package instead of in tsconfig.base.json #10862 (comment)

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Low Risk
Build/tsconfig-only changes with a small Jest coverage threshold tweak; no runtime or API behavior changes.

Overview
Removes per-package compilerOptions.target overrides from several package tsconfig.json files so compilation uses the shared ES2022 default from the root TypeScript config instead of mixed es2017 / es2020 / ES2022 values.

Also lowers json-rpc-engine Jest global branch coverage threshold from 99.6 to 99.59 so CI still passes after the config cleanup.

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