ci: better options to the github action workflows

Author: delfick

.github/workflows/ci.yml

@@ -2,7 +2,15 @@
 
 name: CI tasks
 
-on: [push, pull_request]
+on:
+  pull_request: {}
+  push:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 jobs:
   tests:

.github/workflows/lint.yml

@@ -2,7 +2,15 @@
 
 name: Lint
 
-on: [push, pull_request]
+on:
+  pull_request: {}
+  push:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 jobs:
   lint: