Benchmark using wallclock time instead of CPU time (#3)

This requires upgrading to a newer version of `nixpkgs` to pick up
a newer version of the `tasty-bench` package in order to support
benchmarking using wall-clock time

flake.lock

@@ -18,16 +18,16 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1653936696,
-        "narHash": "sha256-M6bJShji9AIDZ7Kh7CPwPBPb/T7RiVev2PAcOi4fxDQ=",
+        "lastModified": 1661799778,
+        "narHash": "sha256-0fIYh7sOcQOPv0zs+B02Ovx1i40qgx1W1HQJiudCrnQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "ce6aa13369b667ac2542593170993504932eb836",
+        "rev": "7517de391d12a21cd6f6f86df2c42f9ea90237e8",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "22.05",
+        "ref": "master",
         "repo": "nixpkgs",
         "type": "github"
       }
@@ -41,11 +41,11 @@
     },
     "utils": {
       "locked": {
-        "lastModified": 1656065134,
-        "narHash": "sha256-oc6E6ByIw3oJaIyc67maaFcnjYOz1mMcOtHxbEf9NwQ=",
+        "lastModified": 1659877975,
+        "narHash": "sha256-zllb8aq3YO3h8B/U0/J1WBgAL8EX5yWf5pMj3G0NAmc=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "bee6a7250dd1b01844a2de7e02e4df7d8a0a206c",
+        "rev": "c0e246b9b83f637f4681389ecabcb2681b4f3af0",
         "type": "github"
       },
       "original": {