feat: Add @vitest/coverage-istanbul to devDependenciesToRemove (#885)

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## PR Checklist

- [x] Addresses an existing open issue: fixes #759
- [x] That issue was marked as [`status: accepting
prs`](https://github.com/JoshuaKGoldberg/create-typescript-app/issues?q=is%3Aopen+is%3Aissue+label%3A%22status%3A+accepting+prs%22)
- [x] Steps in
[CONTRIBUTING.md](https://github.com/JoshuaKGoldberg/create-typescript-app/blob/main/.github/CONTRIBUTING.md)
were taken

## Overview

Added package `@vitest/coverage-istanbul` to devDependenciestoRemove as
requested in #759

Author: jaas666

Diff for: src/steps/writing/creation/writePackageJson.ts

@@ -8,6 +8,7 @@ const devDependenciesToRemove = [
 	"@babel/preset-react",
 	"@babel/preset-typescript",
 	"@swc/jest",
+	"@vitest/coverage-istanbul",
 	"ava",
 	"babel-jest",
 	"commitlint",