Update releases-validation.yml

Author: MaksimZhukov

.github/workflows/releases-validation.yml

@@ -1,5 +1,6 @@
 name: Validate 'versions-manifest.json' file
-on: 
+on:
+  workflow_dispatch:
   push:
     branches:
       - main
@@ -32,4 +33,4 @@ jobs:
       shell: pwsh
 
     - name: Run simple code
-      run: python -c 'import math; print(math.factorial(5))'
+      run: python -c 'import math; print(math.factorial(5))'