Do not show a stacktrace if a process failed, only the message

* The stacktrace is confusing and rarely useful in that case.

dist/index.js

@@ -68753,9 +68753,13 @@ async function run() {
   try {
     await setupRuby()
   } catch (error) {
+    if (/\bprocess\b.+\bfailed\b/.test(error.message)) {
+      core.setFailed(error.message)
+    } else {
       core.setFailed(error.stack)
     }
   }
+}
 
 // entry point when this action is run from other actions
 async function setupRuby(options = {}) {

index.js

@@ -23,9 +23,13 @@ export async function run() {
   try {
     await setupRuby()
   } catch (error) {
+    if (/\bprocess\b.+\bfailed\b/.test(error.message)) {
+      core.setFailed(error.message)
+    } else {
       core.setFailed(error.stack)
     }
   }
+}
 
 // entry point when this action is run from other actions
 export async function setupRuby(options = {}) {