ci: allow GitHub Actions workflows to be manually triggered

This patch adds a 'workflow_dispatch' trigger to our three GitHub
Actions workflows. This allows us to trigger each workflow by navigating
to the repository's Actions tab, selecting the desired workflow, and
clicking on th 'Run workflow' button.

Signed-off-by: Vincent Fu <vincent.fu@samsung.com>

.github/workflows/ci.yml

@@ -3,6 +3,7 @@ name: CI
 on:
  push:
  pull_request:
+ workflow_dispatch:
 
 jobs:
  build-containers:

.github/workflows/cifuzz.yml

@@ -1,5 +1,5 @@
 name: CIFuzz
-on: [pull_request]
+on: [pull_request, workflow_dispatch]
 jobs:
  Fuzzing:
  runs-on: ubuntu-latest

.github/workflows/qemu.yml

@@ -1,6 +1,7 @@
 name: CI
 
 on:
+ workflow_dispatch:
  schedule:
  - cron: "50 3 * * *" # daily at 4:50 UTC (00:50 EST)