ci: pin the codeql action to SHAs

It's a follow-up to https://github.com/systemd/systemd/pull/21316.

Judging by https://github.com/evverx/systemd/pull/36, Dependabot
supports their release cycle

.github/workflows/codeql-analysis.yml

@@ -29,14 +29,14 @@ jobs:
       uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579
 
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v1
+      uses: github/codeql-action/init@5581e08a65fc3811c3ac78939dd59e7a8adbf003
       with:
         languages: ${{ matrix.language }}
 
     - run: sudo -E .github/workflows/unit_tests.sh SETUP
 
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v1
+      uses: github/codeql-action/autobuild@5581e08a65fc3811c3ac78939dd59e7a8adbf003
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v1
+      uses: github/codeql-action/analyze@5581e08a65fc3811c3ac78939dd59e7a8adbf003