Use jq in release prepare script

[Fryuni]

Summary

Update the release prepare script to mutate package.json with jq instead of brittle sed replacements.

Changes

• Replace the three sed commands with a single jq expression.
• Set the package version from the release tag.
• Strip the leading dist/ prefix from main and types in the copied package metadata.

Testing

• Ran git diff --check.
• Runtime jq smoke test was not run because the environment blocked the command.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@croct/eslint-plugin@497

commit: 5e9ce49