[CI] Changed the Workflow Triggers

Changed the workflow triggers for the test and container workflows such
that they only run when there is a push to master.

Also added concurrency such that if a CI was called on a particular PR
or branch that is already running the CI, it will cancel the old run.
This will prevent useless runs of the CI.

Author: AlexandreSinger

.github/workflows/containers.yml

@@ -1,12 +1,24 @@
 name: Containers
 
 on:
+  # We want to run the CI when anything is pushed to master.
+  # Since master is a protected branch this only happens when a PR is merged.
+  # This is a double check in case the PR was stale and had some issues.
   push:
+    branches:
+      - master
   pull_request:
   workflow_dispatch:
   schedule:
   - cron: '0 0 * * 0' # weekly
 
+# We want to cancel previous runs for a given PR or branch / ref if another CI
+# run is requested.
+# See: https://docs.github.com/en/actions/using-jobs/using-concurrency
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
 
   Image:

.github/workflows/test.yml

@@ -1,12 +1,24 @@
 name: Test
 
 on:
+  # We want to run the CI when anything is pushed to master.
+  # Since master is a protected branch this only happens when a PR is merged.
+  # This is a double check in case the PR was stale and had some issues.
   push:
+    branches:
+      - master
   pull_request:
   workflow_dispatch:
   schedule:
   - cron: '0 0 * * *' # daily
 
+# We want to cancel previous runs for a given PR or branch / ref if another CI
+# run is requested.
+# See: https://docs.github.com/en/actions/using-jobs/using-concurrency
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 env:
   # default compiler for all non-compatibility tests
   MATRIX_EVAL: "CC=gcc-11 && CXX=g++-11"