fixup: only run a single benchmark for take_strings; disable tar

Author: not-matthias

.github/workflows/codspeed.yml

@@ -15,10 +15,9 @@ jobs:
       matrix:
         # IMPORTANT: The binary has to match the architecture of the runner!
         cmd:
-          - testdata/take_strings-aarch64
+          - testdata/take_strings-aarch64 varbinview_non_null
           - echo Hello, World!
           - ls fib.py
-          - tar czf /dev/null fib.py
           - python3 fib.py
         valgrind:
           - "3.26.0"