Add explicit process.exit() to avoid wait for hanging promises

When using the `@actions/cache` library to save cache entries, it seems that one
or more Promises remain unresolved after the save completes.
With Node20 this causes a delay when exiting the process: the default behaviour
now wait for these Promises to complete. Adding an explicit `Process.exit()`
removes the delay, returning to the Node 16 behaviour.

Fixes #1038

dist/main/index.js

@@ -140762,6 +140762,7 @@ function run() {
                 core.info(error.stack);
             }
         }
+        process.exit();
     });
 }
 exports.run = run;

dist/post/index.js

@@ -138072,10 +138072,12 @@ function run() {
         catch (error) {
             if (error instanceof errors_1.PostActionJobFailure) {
                 core.setFailed(String(error));
-                return;
             }
-            handleFailure(error);
+            else {
+                handleFailure(error);
+            }
         }
+        process.exit();
     });
 }
 exports.run = run;

package-lock.json

@@ -35,7 +35,7 @@
         "eslint-plugin-prettier": "5.1.2",
         "jest": "29.7.0",
         "js-yaml": "4.1.0",
-        "npm-run-all": "^4.1.5",
+        "npm-run-all": "4.1.5",
         "patch-package": "8.0.0",
         "prettier": "3.1.1",
         "ts-jest": "29.1.1",

src/main.ts

@@ -29,6 +29,9 @@ export async function run(): Promise<void> {
             core.info(error.stack)
         }
     }
+
+    // Explicit process.exit() to prevent waiting for hanging promises.
+    process.exit()
 }
 
 run()

src/post.ts

@@ -16,11 +16,13 @@ export async function run(): Promise<void> {
     } catch (error) {
         if (error instanceof PostActionJobFailure) {
             core.setFailed(String(error))
-            return
+        } else {
+            handleFailure(error)
         }
-
-        handleFailure(error)
     }
+
+    // Explicit process.exit() to prevent waiting for promises left hanging by `@actions/cache` on save.
+    process.exit()
 }
 
 function handleFailure(error: unknown): void {