fix: update dependency execa to ^0.11.0 (#16871)

Author: renovate[bot]

packages/gatsby-cli/package.json

@@ -23,7 +23,7 @@
     "convert-hrtime": "^2.0.0",
     "core-js": "^2.6.9",
     "envinfo": "^5.12.1",
-    "execa": "^0.8.0",
+    "execa": "^0.11.0",
     "fs-exists-cached": "^1.0.0",
     "fs-extra": "^4.0.1",
     "gatsby-telemetry": "^1.1.15",