Update performance workflow to remove default go version and simplify version handling

The commit removes the default 'stable' value from the go-version input parameter in the performance workflow and simplifies the version handling in the setup-go action to use the input directly without fallback to 'stable'. This ensures consistent version usage across the workflow.

Author: SimoneLazzaris

.github/workflows/performance.yml

@@ -7,6 +7,7 @@ on:
       go-version:
         required: true
         type: string
+        default: 'stable'
   schedule:
     - cron: '0 0 * * *'
 
@@ -49,7 +50,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v6
         with:
-          go-version: ${{ inputs.go-version || "stable" }}
+          go-version: ${{ inputs.go-version }}
       - uses: actions/checkout@v4
       - run: go build -o perf-test-suite ./test/performance-test-suite/cmd/perf-test/
       - name: Run performance tests