add post script

post.js

@@ -0,0 +1,21 @@
+const core = require("@actions/core")
+const exec = require("@actions/exec")
+
+async function main() {
+    try {
+        const container = core.getState("container")
+        core.saveState("container", "")
+
+        if (container) {
+            await exec.exec("docker", [
+                "rm",
+                "--force",
+                container
+            ])
+        }
+    } catch (error) {
+        core.setFailed(error.message)
+    }
+}
+
+main()