Update action.yml to use latest juliaup (#112)

Author: MichaelHatherly

action.yml

@@ -8,7 +8,7 @@ inputs:
   internal-juliaup-version:
     description: '[private internal]. The Juliaup version to install. This is not part of the public API of this action.'
     required: false
-    default: '1.17.4' # Update this value whenever a new release of Juliaup is made.
+    default: '1.18.2' # Update this value whenever a new release of Juliaup is made.
 runs:
   using: 'node20'
   main: 'dist/index.js'