Fix action inputs

Author: cuberoot

.github/workflows/dawn.yaml

@@ -30,25 +30,15 @@ on:
   workflow_call:
     inputs:
       channel:
-        description: "Chromium channel for Dawn"
         required: false
         default: "canary"
-        type: choice
-        options:
-          - stable
-          - beta
-          - canary
+        description: "Chromium channel for Dawn (stable, beta, canary)"
+        type: string
       config:
-        description: "Configuration"
+        description: "Configuration (release or debug)"
         required: false
         default: "release"
-        type: choice
-        options:
-          - release
-          - debug
-    secrets:
-      GITHUB_TOKEN:
-        required: true
+        type: string
 
 jobs:
   get-dawn-version: