ci: move branch name to env var (#104633)

* ci: move branch name to env var

* quoting

.github/actions/setup-grafana-bench/action.yml

@@ -36,9 +36,10 @@ runs:
       shell: bash
       env:
         GH_TOKEN: ${{ steps.generate_token.outputs.token }}
+        BRANCH: ${{ inputs.branch }}
       run: |
         git clone https://x-access-token:${GH_TOKEN}@github.com/grafana/grafana-bench.git ../grafana-bench
 
         cd ../grafana-bench
-        git switch ${{ inputs.branch }}
+        git switch "$BRANCH"
         go install .

.github/actions/test-coverage-processor/action.yml

@@ -28,11 +28,13 @@ runs:
   steps:
     - name: Process Go coverage output
       shell: bash
+      env:
+        COVERAGE_FILE: ${{ inputs.coverage-file }}
       run: |
         # Ensure valid coverage file even if empty
-        if [ ! -s ${{ inputs.coverage-file }} ]; then
+        if [ ! -s "$COVERAGE_FILE" ]; then
           echo "Coverage file is empty, creating a minimal valid file"
-          echo "mode: set" > ${{ inputs.coverage-file }}
+          echo "mode: set" > "$COVERAGE_FILE"
         fi
 
     - name: Report coverage to CodeCov