Fix pre-commit (#565)

Author: dstansby

notebooks/benchmark_vlen.ipynb

@@ -55,10 +55,10 @@
     "    enc = codec.encode(a)\n",
     "    print('decode')\n",
     "    %timeit codec.decode(enc)\n",
-    "    print('size         : {:,}'.format(len(enc)))\n",
-    "    print('size (zstd 1): {:,}'.format(len(zstd1.encode(enc))))\n",
-    "    print('size (zstd 5): {:,}'.format(len(zstd5.encode(enc))))\n",
-    "    print('size (zstd 9): {:,}'.format(len(zstd9.encode(enc))))"
+    "    print(f'size         : {len(enc):,}')\n",
+    "    print(f'size (zstd 1): {len(zstd1.encode(enc)):,}')\n",
+    "    print(f'size (zstd 5): {len(zstd5.encode(enc)):,}')\n",
+    "    print(f'size (zstd 9): {len(zstd9.encode(enc)):,}')"
    ]
   },
   {