Update GitHub actions

Author: rrrene

.github/workflows/credo.yml .github/workflows/code-scan-sarif.yml

@@ -34,15 +34,15 @@ jobs:
       contents: read # for actions/checkout to fetch code
       security-events: write # for github/codeql-action/upload-sarif to upload SARIF results
       actions: read # only required for a private repository by github/codeql-action/upload-sarif to get the Action run status
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
       matrix:
         otp: [version]
         elixir: [version]
     steps:
       - uses: actions/checkout@v3
-      - uses: erlef/setup-beam@988e02bfe678367a02564f65ca2e37726dc0268f
+      - uses: erlef/setup-beam@v1
         with:
           otp-version: ${{matrix.otp}}
           elixir-version: ${{matrix.elixir}}