Bump execa from 5.1.1 to 6.0.0

Bumps [execa](https://github.com/sindresorhus/execa) from 5.1.1 to 6.0.0.
- [Release notes](https://github.com/sindresorhus/execa/releases)
- [Commits](sindresorhus/execa@v5.1.1...v6.0.0)

---
updated-dependencies:
- dependency-name: execa
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -39,7 +39,7 @@
     "chalk": "^4.1.1",
     "common-tags": "^1.8.0",
     "ember-template-recast": "^4.1.4",
-    "execa": "^5.0.0",
+    "execa": "^6.0.0",
     "fs-extra": "^9.1.0",
     "globby": "^11.0.2",
     "import-cwd": "^3.0.0",