ci: pin third-party actions to commit SHAs (#5869)

* ci: pin third-party actions to commit SHAs

Pin third-party GitHub Actions in workflow files to immutable 40-char
commit SHAs per the org security policy. Mutable refs like @v4 can be
silently re-pointed by a compromised upstream; SHAs cannot. Trailing
version comments let Dependabot/Renovate continue to manage updates.

Related to [COR-51](https://linear.app/crewai/issue/COR-51).

* ci: disable persist-credentials in pip-audit checkout

Address CodeRabbit feedback on PR #5869: the pip-audit workflow is
read-only and never needs an authenticated git context, so opt out of
persisting the GITHUB_TOKEN in the local git config per the
actions/checkout security guidance.

.github/workflows/codeql.yml

@@ -59,7 +59,7 @@ jobs:
         # your codebase is analyzed, see https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/codeql-code-scanning-for-compiled-languages
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
 
     # Add any setup steps before running the `github/codeql-action/init` action.
     # This includes steps like installing compilers or runtimes (`actions/setup-node`
@@ -69,7 +69,7 @@ jobs:
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v4
+      uses: github/codeql-action/init@9e0d7b8d25671d64c341c19c0152d693099fb5ba # v4.35.5
       with:
         languages: ${{ matrix.language }}
         build-mode: ${{ matrix.build-mode }}
@@ -98,6 +98,6 @@ jobs:
         exit 1
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v4
+      uses: github/codeql-action/analyze@9e0d7b8d25671d64c341c19c0152d693099fb5ba # v4.35.5
       with:
         category: "/language:${{matrix.language}}"