Bump execa from 3.4.0 to 4.0.2

Bumps [execa](https://github.com/sindresorhus/execa) from 3.4.0 to 4.0.2.
- [Release notes](https://github.com/sindresorhus/execa/releases)
- [Commits](sindresorhus/execa@v3.4.0...v4.0.2)

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

Author: dependabot-preview[bot]

package.json

@@ -25,7 +25,7 @@
     "cac": "^6.5.2",
     "chalk": "^3.0.0",
     "download": "^7.1.0",
-    "execa": "^3.3.0",
+    "execa": "^4.0.2",
     "majo": "^0.10.1",
     "ora": "^4.0.2",
     "s3rver": "^3.3.0",