Merge pull request #3841 from adamdmharvey/improve-codeql

build: Improve CodeQL flow

.github/workflows/codeql-analysis.yml

@@ -11,6 +11,11 @@ on:
   pull_request:
     # The branches below must be a subset of the branches above
     branches: [master]
+    # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#scanning-pull-requests
+    paths-ignore:
+      - '**/*.md'
+      - '**/*.yml'
+      - '**/*.yaml'
   schedule:
     - cron: '0 8 * * 6'
 
@@ -36,11 +41,6 @@ jobs:
           # a pull request then we can checkout the head.
           fetch-depth: 2
 
-      # If this run was triggered by a pull request event, then checkout
-      # the head of the pull request instead of the merge commit.
-      - run: git checkout HEAD^2
-        if: ${{ github.event_name == 'pull_request' }}
-
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v1