ci: update concurrency/"on" to match some best practices

.github/workflows/sqlite3-ruby.yml

@@ -1,6 +1,19 @@
 name: CI
-
-on: [push, pull_request]
+concurrency:
+  group: "${{github.workflow}}-${{github.ref}}"
+  cancel-in-progress: true
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+      - v*.*.x
+    tags:
+      - v*.*.*
+  pull_request:
+    types: [opened, synchronize]
+    branches:
+      - '*'
 
 jobs:
   CI: