ci: add workflow_dispatch to allow manual CI runs

.github/workflows/build.yaml

@@ -7,6 +7,7 @@ on:
   pull_request:
     branches:
     - '**'
+  workflow_dispatch:
 
 jobs:
   build-linux-run-tests:

.github/workflows/cppcheck.yml

@@ -7,7 +7,7 @@ on:
   pull_request:
     branches:
       - '**'
-
+  workflow_dispatch:
 jobs:
   cppcheck:
     runs-on: ubuntu-latest

.github/workflows/static-analysis.yml

@@ -5,7 +5,7 @@ on:
     branches: [ master, 2.0.x ]
   pull_request:
     branches: [ master, 2.0.x ]
-
+  workflow_dispatch:
 jobs:
   analyze:
     name: Analyze

README.md

@@ -69,6 +69,25 @@ See the "COPYING", "LICENCE", and "NOTICE" files for legal
 information. The license is the same as for CUPS, for a maximum of
 compatibility.
 
+---
+
+## DEVELOPMENT AND CI/CD
+
+### CodeQL Static Analysis Configuration
+
+This repository uses a custom GitHub Actions workflow for CodeQL static analysis located at `.github/workflows/static-analysis.yml`. To ensure accurate analysis and avoid conflicts with GitHub's default settings, the following repository configurations are required:
+
+1. **Enable Advanced Setup**:
+   - Go to **Settings** -> **Code security and analysis**.
+   - Under **Code scanning**, locate **CodeQL analysis**.
+   - If "Default" is enabled, click the three dots (...) and select **Switch to advanced**.
+2. **Disable Default Setup**: 
+   - The "Default" setup must be disabled for the custom workflow to upload results successfully.
+3. **Custom Workflow Dependencies**:
+   - Our custom workflow is designed to install specific project dependencies and perform a manual build before the analysis. This ensures that CodeQL has a complete build graph for the C sources in this repository.
+
+*Note: If the Default setup is active, GitHub may reject the results uploaded by the manual workflow, causing the CI job to fail.*
+
 ## LINKS
 
 ### cups-filters