ci: codeql: add the language to the category

For consistency with the auto-generated yaml:

    - name: Perform CodeQL Analysis
      uses: github/codeql-action/analyze@v3
      with:
        category: "/language:${{matrix.language}}"

Documentation:

* https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/customizing-your-advanced-setup-for-code-scanning#changing-the-languages-that-are-analyzed
* https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/customizing-your-advanced-setup-for-code-scanning#configuring-a-category-for-the-analysis

Author: kmk3

.github/workflows/check-c.yml

@@ -162,3 +162,5 @@ jobs:
 
     - name: Perform CodeQL Analysis
       uses: github/codeql-action/analyze@b7bf0a3ed3ecfa44160715d7c442788f65f0f923
+      with:
+        category: "/language:cpp"

.github/workflows/check-python.yml

@@ -56,3 +56,5 @@ jobs:
 
     - name: Perform CodeQL Analysis
       uses: github/codeql-action/analyze@b7bf0a3ed3ecfa44160715d7c442788f65f0f923
+      with:
+        category: "/language:python"