chore(deps-dev): bump execa from 5.1.1 to 9.5.2

Bumps [execa](https://github.com/sindresorhus/execa) from 5.1.1 to 9.5.2.
- [Release notes](https://github.com/sindresorhus/execa/releases)
- [Commits](sindresorhus/execa@v5.1.1...v9.5.2)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

packages/tachyons/package.json

@@ -12,7 +12,7 @@
   "devDependencies": {
     "@theme-ui/css": "workspace:^",
     "babel-polyfill": "^6.26.0",
-    "execa": "^5.0.0"
+    "execa": "^9.5.2"
   },
   "publishConfig": {
     "access": "public"

packages/tailwind/package.json

@@ -11,7 +11,7 @@
   "devDependencies": {
     "@theme-ui/css": "workspace:^",
     "babel-polyfill": "^6.26.0",
-    "execa": "^5.0.0",
+    "execa": "^9.5.2",
     "tailwindcss": "^3.0.15"
   },
   "publishConfig": {