ci: pin some workflows to SHAs

to let Dependabot keep track of them using SHAs

codeql-actions doesn't point to SHAs because it isn't clear
whether Dependabot supports their release cycle mentioned
at https://github.com/github/codeql-action/issues/307

.github/workflows/build_test.yml

@@ -30,6 +30,6 @@ jobs:
     env: ${{ matrix.env }}
     steps:
       - name: Repository checkout
-        uses: actions/checkout@v1
+        uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579
       - name: Build check (${{ env.COMPILER }}-${{ env.COMPILER_VERSION }})
         run: sudo -E .github/workflows/build_test.sh

.github/workflows/cifuzz.yml

@@ -44,7 +44,7 @@ jobs:
           dry-run: false
           sanitizer: ${{ matrix.sanitizer }}
       - name: Upload Crash
-        uses: actions/upload-artifact@v1
+        uses: actions/upload-artifact@27121b0bdffd731efa15d66772be8dc71245d074
         if: failure() && steps.build.outcome == 'success'
         with:
           name: ${{ matrix.sanitizer }}-artifacts

.github/workflows/linter.yml

@@ -25,7 +25,7 @@ jobs:
           fetch-depth: 0
 
       - name: Lint Code Base
-        uses: github/super-linter@v3
+        uses: github/super-linter@fd9c4286d3de3fdd9258a395570cae287f13f974
         env:
           DEFAULT_BRANCH: main
           # Excludes: