gh-action: allow manual bench run with filer

Author: robinhundt

.github/workflows/bench.yml

@@ -4,6 +4,12 @@ on:
   push:
     branches:
       - "main"
+  workflow_dispatch:
+    inputs:
+      filter:
+        description: 'Optional filter for cargo bench (e.g., a specific benchmark name)'
+        default: ''
+        required: false
 
 jobs:
   benchmarks:
@@ -32,9 +38,9 @@ jobs:
           bencher run \
           --project cryprot \
           --token '${{ secrets.BENCHER_API_TOKEN }}' \
-          --branch main \
+          --branch '${{github.ref_name}}' \
           --testbed ubicloud-standard-4 \
           --threshold-measure latency \
           --threshold-test t_test \
           --threshold-upper-boundary 0.99 \
-          'cargo bench'
+          'cargo bench ${{ github.event.inputs.filter }}'