Remove flawfinder.

It's too noisy, lacks context

.github/workflows/flawfinder.yml

@@ -1,33 +0,0 @@
-name: flawfinder
-
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    # The branches below must be a subset of the branches above
-    branches: [ master ]
-  schedule:
-    - cron: '17 3 * * 5'
-
-jobs:
-  flawfinder:
-    name: Flawfinder
-    runs-on: ubuntu-latest
-    permissions:
-      actions: read
-      contents: read
-      security-events: write
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@v3
-
-      - name: flawfinder_scan
-        uses: david-a-wheeler/flawfinder@8e4a779ad59dbfaee5da586aa9210853b701959c
-        with:
-          arguments: '--sarif ./'
-          output: 'flawfinder_results.sarif'
-
-      - name: Upload analysis results to GitHub Security tab
-        uses: github/codeql-action/upload-sarif@v2
-        with:
-          sarif_file: ${{github.workspace}}/flawfinder_results.sarif