chore(actions): allow forcing snapshots deployment

.github/workflows/validation.yml

@@ -3,6 +3,12 @@ on:
   push:
     branches: [development, vaadin-24.4, vaadin-23]
   workflow_dispatch:
+    inputs:
+      force-deploy:
+        description: "Force snapshot deploy"
+        default: false
+        required: false
+        type: boolean
   pull_request_target:
     types: [opened, synchronize, reopened, edited]
 permissions:
@@ -302,7 +308,7 @@ jobs:
     permissions:
       contents: read
       packages: write
-    if: ${{ success() && github.event_name == 'push' && github.ref_protected && needs.changes.outputs.deploy-required == 'true'}}
+    if: ${{ success() && github.ref_protected && ((github.event_name == 'push' && needs.changes.outputs.deploy-required == 'true') || (github.event_name == 'workflow_dispatch' && github.event.inputs.force-deploy == 'true'))}}
     steps:
       - uses: actions/checkout@v4
         with: