ci: remove security vulnerability scan workflow (#5266)

.github/workflows/security.yml

@@ -1,21 +0,0 @@
-name: Security Scan
-
-on:
-  schedule:
-  - cron: "0 13 * * 1"
-  push:
-    branches:
-    - master
-    - dev
-  pull_request:
-    branches:
-    - master
-    - dev
-
-jobs:
-  vulncheck:
-    name: Scan for vulnerabilities in Go code
-    runs-on: ubuntu-latest
-    steps:
-    - name: govulncheck
-      uses: golang/govulncheck-action@v1