Update dependency @actions/exec to v3

Update @actions/exec from 2.0.0 to 3.0.0

Change-type: patch

Author: balena-renovate[bot]

package-lock.json

@@ -68,7 +68,7 @@
   },
   "dependencies": {
     "@actions/core": "^2.0.0",
-    "@actions/exec": "^2.0.0",
+    "@actions/exec": "^3.0.0",
     "@actions/github": "^8.0.0",
     "balena-sdk": "^23.0.0"
   },