[CONFIG] [Github Actions] Avoid run on "push" for dependabot triggered actions.

Workflows triggered by Dependabot on the "push" event run with read-only access. Uploading Code Scanning results requires write access. To use Code Scanning with Dependabot, please ensure you are using the "pull_request" event for this workflow and avoid triggering on the "push" event for Dependabot branches. See https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/customizing-your-advanced-setup-for-code-scanning#scanning-on-push for more information on how to configure these events.

https://stackoverflow.com/a/57903434/6366150

Author: Gonzalo Diaz

.github/workflows/snyk-code.yml

@@ -4,11 +4,13 @@
 # yamllint enable rule:line-length
 
 ---
-
 name: .NET Snyk Code analysis
 
 on: # yamllint disable-line rule:truthy
   push:
+    branches:
+      - "**" # matches every branch
+      - "!dependabot/**" # excludes master
   pull_request:
   workflow_dispatch: